William Mercury

William Mercury is an S-Class Mage of the Dragon Gunfire guild, and a magic teacher. He's learned and taught various magics, and is capable of wielding the Flame of Rebuke. He had been tracking the activities of the country of Othrys for some time, due to a job he received from the Magic Council, and hoping to bring them down for the sake of Ishgar. However he was captured and tortured by Othrys, starting the Dragon Gunfire-Othrys War. After this event his mission was voided, and he was able to remain at the Nidavellir. He was also one of the few Dragon Slayers that remained in Dragon Gunfire after the Civil War between the guild members, leaving him as one of Aether Cade's most trusted companions. Due to his power, he is considered the second strongest mage of Dragon Gunfire, just after Miriam Cade.

Appearance
William has slicked back, white hair, black eyes and coffee brown skin. He wears a red coat with metal ovals near the end of the sleeves, and two crosses with a rope that keeps his coat together. He wears this coat over black armor, which covers the entirety of his body. The armor has white lines that mark his rather muscular body, and metal belt, iron-toed shoes. Overall, his attire is similar to that of a priest. Under his armor is a skin tight black suit. Like all Dragon Slayers, William also sports sharpened canines.

Personality
William is a very level-headed individual, to a degree where he can't be made angry unless he wants to be. He's completely mastered his emotions, in order to better use his "Flames of Emotion" when using the Flame of Rebuke, as well as his calmer nature giving him complete control over the output of his magical energy. Although the emotion he uses most often is joy, and he often smiles after certain happy events, such as his students mastering techniques.

He also is incredibly kind, being willing to train any student, and will often compliment them on jobs. He cares deeply for all of his students, not showing any favoritism or disappointment in them. Even his star pupil, Aether Cade, is treated just like all of his other students. He often tries to maintain contact with all of his students, often visiting them to test their growth, and simply just so he can see them from time to time. During the Grand Magic Games, after William realized his popularity was due to the word of mouth of his students, he cried with joy and pride over the loyalty and devotion of his students.

Beneath his calm demeanor however, William has a crippling fear of loss. He sees the loss of a loved one, through them being killed or otherwise, as him failing them. This is the only thing that can truly make him go off the edge, and can cause him to even go on a Dragon Force fueled rampage, as shown during the first round of the Grand Magic Games in X800. Although, he still acts as he did before this event, the ordeal of fear he went through during the Grand Magic Games still haunts him, giving him a fear, and immense loathing towards Cronus Saturnalia, something he hadn't developed, even when Cronus had been torturing him.

William believes wholeheartedly in Aether Cade's ideals. He believes that Dragon Slayers are the chosen few of the Dragons to protect, and care for the larger minority. He believes that Dragon Slayers are not superior to any human, whether they're a Mage or not. William also believes that there is a point in one's mental state where they gain complete control in their magical output, obtainable through gaining serenity through emotional control. William is living proof of that, as his power is greatly derived from his controlled emotions, never giving into taunts, and having masterful control of his magical energy. He tries to teach this method of control to all of his students, with varying degrees of success. Like all other Dragon Slayers, William also possesses a voracious appetite, and suffers from debilitating motion sickness.

History
William was initially trained by the Cavern Dragon, Mantle, training him in the art of Cavern Dragon Slayer Magic. However, the Dragon succumbed to wounds it received from Acnologia over the past 400 years, and died, leaving him in the care of the Dragon Gunfire guild.

As a child, William was tormented similarly to Aether in order to train him. His father, and other Dragon Slayers would often beat him in order to toughen him up. He refused to break however, as he knew that if he did, they won. This expierience led William to learn how to control his magical power through the control of his emotions, leading him to becoming a very powerful individual. When the civil war in Dragon Gunfire broke out, William was one of the Dragon Slayers that decided to join Aether's pro-integration side. His participation in the war demonstrated his true power to his oppressors, defeating them swiftly and easily. Shortly after the war, he left the guild on a job to bring down the sinister country of Othrys. During this time, he also taught many students how to use magic, or better magical control, including Aether Cade.

He eventually encountered Cadmus Zephyrus. In a climactic duel he defeated and killed him, thwarting a plan he had to retake Dragon Gunfire. William then claimed his Dragon Lacrima as his own, and implanted it into himself.

Synopsis
A New Teacher: Seraph vs William

Dragon Gunfire's Promotional Trial: A Battle of Strength and Wit

Othrys Arc: The City on the Mountains

Grand Magic Games X800

From One Angel to Another: Hino's Retribution

Magic and Abilities
Cavern Dragon Slayer Magic: A form of Dragon Slayer Magic that allows William to generate, manipulate, and consume earth in order to heal injuries. William is also capable of freely altering the landscape he's in, as long as the landscape he's altering is made from earth. This includes rock, sand, stone, magma or lava, and gems. William is also capable of altering magical attacks made from any of these materials, but to a limited degree. The same is true for precious metals containing a certain amount of earth. Any earth he uses from the surrounding earth is also comparatively weaker than the earth he, himself, creates. The stone he creates from his own person is denser, and more durable than any natural form of earth, and by condensing earth for a certain period of time, he can create even denser gems. Earth that he manipulates, that didn't originate from his own person, can also be increased in density if William focuses on doing that. William can also use his magic as a ground for electricity-based spells, using this ability to his advantage in his battle against Hino Sontara, the a Lightning Dragon Slayer. This magic also grants William enough jaw strength to easily bite, chew, and consume stone of any grade. Gale Dragon Slayer Magic: William acquired this magic by killing Cadmus Zephyrus and implanting his Dragon Lacrima into his body. As this magic comes solely from a lacrima, it is comparatively weaker than his Cavern Dragon Slayer Magic. This allows William to eat external sources of air in order to increase his own power, and heal injuries, but it depends on eternano content in the air. This has more destructive power than Sky Dragon Slayer Magic, but lacks its healing abilities. The wind William can produce is hurricane strength, capable of uprooting trees, and pushing away boulders. By focusing his wind, he can even bore holes through stone, and break metal. Due to this magic, William has an incredible oxygen capacity, and can sense the smallest disturbances in the wind. William generally uses this in tandem with his Cavern Dragon Slayer Magic to deal damage by focusing the wind via wind tunnels. This makes up for his comparative lack of power when using this magic. He can also manipulate the wind in order to fly. Dragon Force: The ultimate form of Dragon Slayers. By consuming large quantities of eternano rich earth, William is capable of assuming this form. William is also capable of entering Dragon Force by being overwhelmed with emotion. However, due to William's mastery over his emotions, all he really needs to do is focus them all into a chosen emotion. Normally he chooses joy, but can be inclined to choose rage or any other emotion. When utilizing Dragon Force, William is covered in flesh-colored scales. His control over earth is increased dramatically, allowing him to near instantly condense earth into gems, which are capable of redirecting light-based attacks, blinding his opponents with the glare from light, and increase the overall power of his physical offense and defense. The gems are considered to be even stronger than diamond, with William being capable of shattering said material in a single blow. The winds he produces also increase in power, allowing for him to create even stronger hurricane winds, capable of tossing around even the heaviest of objects, such as vehicles that weigh tons, and thrashing around opponents while simultaneously robbing them of oxygen. When activating Dragon Force, William also gains a layer of earth over his hands in the shape of Dragon claws, similarly to Erik when he activates his Dragon Slayer Magic. These claws, like the rest of his earth, can instantly be hardened into gems. His aura also emanates a constant stream of pressurized air, making it difficult to get close to him, and even more difficult to breath when near him, causing them to feel lightheaded due to hyperventilation. William is only unaffected by this aura as it doesn’t take shape until it gets a few inches away from his body. The more emotional William gets while in Dragon Force, the more Draconic his body becomes, gaining more scales, and sharpening his fingernails into Dragon talons. The increase in magic power can even blow off his clothes, more specifically his shirt and upper body armor. Dragonification: William bathed in the blood of his Dragon master Mantle, per his request, after he died. This increased his overall power, and also gave him access to this transformation, which he slowly learned to control overtime. Due to a lack of Dragonification anti-bodies, William gained the ability to transform into a small, Draconoid creature, similar in appearance to the Rock Dragon that attacked Fiore in X791 with the other six Dragons. This form increases his strength, speed, durability, and overall magic power. The new scales provide extra resistance to attacks, but not immunity to non Dragon Slayer spells. He also is provided with razor-sharp claws, and increased control over his Dragon Slayer Magic. This increased power even allows him to effortlessly change the entire landscape he's in with his magic, barely even showing any movement. The size and power of his other spells are also dramatically increased. His power is said to increase tenfold in this state, granting him even more power than his Dragon Force. Despite appearing as the Rock Dragon, William can still use his Gale Dragon Slayer Magic. He is also capable of partial transformations, covering certain parts of his body in his rock scales for increased defense and offense, but they aren't as strong as if he had used the full transformations. This state can be activated when William is in Dragon Force, or from his base state. The more Dragon blood he bathes in the more powerful this transformation becomes. Flame of Rebuke: William creates powerful golden flames. Unlike the usual golden flames however, William uses a weaker version of them, preventing them from activating their fullest effects, but allowing him to continuously use them. These flames are highly versatile, and upon contact with normal beings, the flames suddenly become alive, so to speak, and latch onto them, sucking up their energy which allows the fire to intensify. William can shape the flames into numerous structures in order to attack. These flames are unable to be extinguished nor are they able to be taken control of by a secondary-source; they move and burn according to the will of the user. The flames act completely separately to regular flames, and pursue an enemy relentlessly with great speed, accuracy and strength. They are also hard to douse, as they continue burning even when struck with a large amount of water. When faced with opposing fire spells, the flames consume them in order to boost their strength and quantity. The Flame of Rebuke, while simultaneously leeching magical energy from the opponent upon contact, also pulverizes them viciously. Despite William's flames being weaker, allowing him to use them for longer amounts of time, he still uses them as a last-resort against powerful enemies, as he's incapable of maintaining them for too long. Originally his limit was five named spells before collapsing, although he could push himself further in order to use a sixth spell. After a long time of training, William gained the ability to use ten named spells. Also, William only needs to activate the flames once, as they cover his body in the golden flames, protecting him from oncoming attacks without harming himself. He was capable of using this magic in order to defend himself from Seraph Kinmichi, including his Iron Dragon's Crushing Fang, and burn away his magic. Sound Magic: William uses this magic more so supportively as opposed to offensively. He uses it in conjunction with his Cavern Dragon Slayer Magic to utilize echolocation, increasing his efficiency in caves.
 * Cavern Dragon's Roar: William inhales deeply, and fires a large stream of earth from his mouth in the shape of a spiraling sandstorm, with rocks in the center. Said attack is powerful enough to bore through mountains. This spell was strong enough to overpower Hino Sontara's own Lightning Dragon's Roar, and redirect the power of both spells back into his face.
 * Cavern Dragon's Earth Destruction: William strikes the ground and destroys the earth in a relatively large, explosive radius, which not only destroys his foes' footing, but also leaves them bombarded with the extremely large boulders fractured from the ground. This attack is also capable of creating sinkholes when applied properly.  When used, this spell was capable of easily destroying the floor of the Domus Flau, something that only Sting Eucliffe’s White Dragon’s Holy Breath had managed to do before.  This is even more incredible due to the fact that Sting was in Dragon Force, while William was able to use this spell with no adverse effects without the aid of Dragon Force.
 * Cavern Dragon's Mountain Armor: William covers himself in highly condensed Earth, as strong and as durable as a mountain. This gives William a great deal of defense, and enhanced physical power that can even destroy hard metals, the likes of black steel and adamantine. He can also use it in order to cover his foes or friend, choosing whether or not to allow them to move.  This allows him to protect allies, to take away enemies’ ability to move.  He used this variation to defeat Amunet Fukayna, stopping her moving.  This spell has strong enough defense to completely protect William from Reed Yuriko's Fire-Make: Scattered Arrows, and temporarily aid William in matching Hino Sontara's Dragon Slayer's Secret Art.
 * Cavern Dragon's Crush Claw: William can use this spell when either his entire body, or just up to one of his forearms are covered in earth. The earth on his forearm is more well sculpted, specifically the tips of his fingers being sharpened into claws, reminiscent to those of a Dragon's.  With his claws spread apart and his palm open, save for his claws pointing at his opponent, he then slams his claws into his opponent.  The mere blunt force of this spell is great enough, but the added claws also dig into the skin of his target, piecing through their body and dealing even more damage.  This spell was strong enough that Hino Sontara's Lightning Dragon's Talon was barely able to redirect it, and it would've done crushing damage to his body.
 * Cavern Dragon's Rock Spire: William summons large, sharp spires of earth from the ground. This can either be used defensively in order to block attacks, or offensively in order to strike airborne enemies. William can also fire the spires out of the ground at enemies that are too high for their normal range.
 * Cavern Dragon's Sinkhole: William moves the earth below his opponent, causing them to fall into the earth. William can then close the hole so that his opponent is unable to escape, unless they have enough power to smash through the ground.
 * Cavern Dragon's Stone Edge: William condenses several stones into a small ball, and continues to compress them until they begin blasting stone shards off from the main ball like a machine gun. This attack is incredibly rapid and fast, dealing significant damage to opponents.  Each rock is like an armor piercing bullet.
 * Cavern Dragon's Rock Wrecker: William punches the ground, creating a circle around a large area of earth. He then pulls that large amount of earth from the ground, and throws it at his opponent. The strength of this attack is dependent on the amount of earth available to him, and how heavy a stone he can lift and throw effectively.
 * Cavern Dragon's Tunneling Earth: William dives into the ground, and tunnels through it, moving the earth, and enabling him to move through it like air. This allows William to set up underground traps in seconds, or easily sneak up on enemies. William was able to use this spell to avoid Pluto Morior's Sinkhole, and then deal a surprise attack to him from below, and can be applied inside of the Dragon's Den in order to attack from all directions.
 * Dragon Slayer's Secret Art:
 * Dragon's Peak: To begin this spell, William moves his hands upwards, moving a great amount of earth. From the ground, a large mountain then spurts up, having William ride it to the peak of the mountain. William can then manipulate the terrain of the earth, having absolute control over what it does.  He can generate rockslides, mudslides, or even a volcanic eruption from this mountain.  The eruptions are not limited to the top of the mountain however, and can explode from any section of the mountain.  He can also sense everything that's going on in the mountain due to his seismic sense.  This makes approaching William very dangerous while this spell is active, and making it unwise to approach him from the ground.  Even when approaching from the sky, William is still capable of using ranged attacks by blasting his opponents with rocks or magma from the cliffside.
 * Dragon's Den: William moves the earth creating a shell of earth over him and his opponent. William is capable of freely manipulating the earth inside the shell, being capable of sending pillars, spires, or creating sinkholes from any direction. He can even completely change the shape or layout if he so desired. The Den is pitch black inside, giving William the advantage, even over other Dragon Slayers, due to his usage of echolocation, and that the sounds bounce off of the walls, leaving it difficult to track him by sound. Essentially, William has created a cave with no entrances or exits. In the event that someone tries to break free, William can fix the den by utilizing surrounding earth.
 * Gale Dragon's Roar: William inhales deeply, and blasts a large amount of wind from his mouth. This spell is capable of uprooting trees, and pushing back opponents great distances. It's power can even rattle the internal organs of those it's used against
 * Gale Dragon's Wind Tunnel: William erects walls of earth around his target, creating linear paths for his wind to follow. He then fires a large blast of wind from his hands, increasing its velocity with the walls, and throwing the target all around the area, crashing into the earth surrounding the area. This spell was able to both injure, and put put the fires of Reed Yuriko.
 * Gale Dragon's Cataclysm: William moves his hand in a circular motion, creating a powerful tornado. He then throws it, causing it to rapidly increase in power and size. The tornado can toss around adversaries, and pick up debris on the battlefield, allowing for it to strike enemies, damaging them even more. This spell was strong enough to counter, and overpower the fire of Reed Yuriko.
 * Gale Dragon's Storm Leg: William covers his hand in high velocity winds, then delivers a devastating kick.  Unlike his other Gale Dragon Slayer Magic spells, this one focuses more on piercing power as opposed to blunt damage.  The winds are capable of cutting through even the likes of steel, and titanium with enough force behind the kick. William can also use a ranged version of this spell by kicking his leg through the air, generating a shockwave of wind with the same properties.
 * Gale Dragon's Tempest Fist: William aims his fist at his opponent, generally from inches away from their body.  He then fires a powerful stream of air from his fist, with strength equivalent to that of one of his earth-clad punches. The wind also generates a powerful shockwave through his opponent that deals internal damage as well. This spell caused Reed Yuriko great pain, causing him to fly off balance, despite him gaining some distance from William, and created a great deal or collateral damage in the forest he was fighting Hino Sontara in, despite him being airborne at the time, as well as injuring Hino when he attempted to avoid the brunt of the spell. The force was enough that if his Exceed, Spirit, had not caught him, Spirit stated he would've been destroyed like the landscape.
 * Gale Dragon's Wind Step: William uses the winds in order to propel himself at accelerated speeds.  This speed is incredibly fast, moving so fast that William appears to be disappearing and reappearing.  He can use this spell on the ground to increase running speed, or in the air for his flying speed.  This spell was so fast that Reed Yuriko could not react to William's movements, leaving him open to be attacked from behind, outpace and surprise both Amunet Fukayna and Shuya Toriyama, and avoid and counterattack assaults from Hino Sontara that were aided by his Lightning Dragon Slayer Magic. It even managed to aid William in temporarily matching Hino's Dragon Slayer's Secret Art.
 * Dragon Slayer's Secret Art:
 * Dragon's Shock Cannon: William covers both his fists in wind and runs up to his opponent.  He then slams both of his fists into his opponent, one hand above the other, and blasts them with a highly powerful burst of wind that acts as an internal shockwave, the wind rattling his target's organs.  This allows William to bypass physical defenses, and deal even more damage than he did previously.  This spell is comparable to the Gale Dragon's Tempest Fist, but one fist with the Shock Cannon is twice as powerful as the Tempest Fist.  The fact that he's using both hands for this spell means that it is four times as powerful as the Gale Dragon's Tempest Fist.  When this spell makes contact it can even be seen exiting the target's body as a shockwave that can continue to bore through stone objects. This is William's most powerful Gale Dragon Slayer Spell.
 * Hidden Cavern Form - Gem Armor: A Dragon Force enhanced version of William's Cavern Dragon's Mountain Armor. William condenses the earth of his Moutain Armor into even harder gems. This allows him to increase strength and and defense even further. He is capable of reflecting light-based attacks off of his armor, and his gems are far more heat resistant than his earth. He can also fire off fragments of his Gem Armor in order to impale or strike opponents with them, or even create blades on his body made from the powerful gems.
 * Flight: Despite the earthen appearance of his new wings, William is capable of natural flight without the aid of magic with them.  His flight speed is incredibly fast, allowing him to move from place to place in instants, mostly increased in speed by propulsion from his Gale Dragon Slayer Magic. The wings are also very durable, and can be used to block attacks. The wings are, of course, made from the same scales as William's regular Dragon scales.
 * Enhanced Strength: William's already incredible strength is increased even further in this form. He's easily capable of lifting incredibly heavy objects, that ordinarily he couldn't lift, or would at least take a more considerable amount of time.
 * Enhanced Durability: William's scales increase his already immense durability, allowing him to deflect attacks, and more easily resist damage from attacks that normally would be detrimental to his body.  His new Rock Dragon scales are even sturdier than his normal Cavern Dragon's Mountain Armor, and he can also harden them into precious gems for increased offensive and defensive capabilities.
 * Berate: William gathers the Flame of Rebuke in his mouth and blasts a column of golden flames at his opponent, burning away other attacks.
 * Flame Scolding Arrow: William forms an arrow using the Flame of Rebuke and fires, the arrow moving at an incredibly alarming rate.  When the arrow makes contact, it covers who, or whatever it hits in burning flames that greatly damage the affected area, almost appearing as though they exploded onto the target's body.
 * Admonishing Swords: William creates many swords made from the fire of the Golden Flames of Rebuke and sends them at his opponent.  The swords ignite whatever they touch in a large amount of golden flames.  This spell was capable of defending himself from Seraph Kinmichi's Iron Dragon's Roar, completely destroying the attack.
 * Retribution: William activates the Flame of Rebuke in his hand, preparing a punch.  He then covers his fist in stone using his Cavern Dragon Slayer Magic.  This seals in the flames, increasing the power of his punch to incredible degrees.  William learned this spell to combat fire based Slayers, so that they couldn't eat his Flame of Rebuke, and enter Dragon Force.  This is because the fire and earth are so intertwined that a Slayer cannot eat them unless they can consume both elements. When the attack goes off it creates a brilliant explosion that anyone near the epicenter will also be affected by the spell.  This spell was strong enough to punch a hole into a clone of Seraph Kinmichi, and used the resulting explosion in order to prevent Seraph from counterattacking.

Telepathy: William can communicate over long distances with his telepathy, even being capable of communicating with Aether from the guild hall from Othrys. He can also use his telepathy to read his opponents attacks and react accordingly.

Masterful Energy Manipulation: William is capable of manipulating his eternano due to his mastery over his emotional state. This allows him to better control his energy, never using any more than he needs to in contact. William can also use this skill in order to cover his body in a thin layer of eternano, and negate the defensive capabilities of opposition that become intangible. This skill is very invaluable against enemies that use magics like Water, or can otherwise transform into their elements. Out of all the people he trained in this emotional style of magical control, William is the other one to have completely mastered this technique, even surpassing Aether Cade in magical control.

Enhanced Senses: As a Dragon Slayer, William has enhanced senses of smell and hearing. However, William's Cavern Dragon Slayer Magic also gives him an enhanced sense of touch, allowing for him to sense vibrations in the ground. He refers to this enhanced sense of touch as his "Seismic Sense". This sense of touch proved valuable in two separate occasions during the Grand Magic Games of X800, allowing him to sense three pitfalls, and navigate through a maze without his sense of smell, taste, or sight. William can also use his enhanced hearing to use echolocation.

Master Hand to Hand Combatant: William mastered hand to hand combat to use in conjunction with his magic. He can easily fist fight against opponents, including the most skilled unarmed combatants. His skill even allows him to fight multiple opponents at once. He was skilled enough to outmatch Reed Yuriko, who is known as an expert hand to hand combatant, as well as Amunet Fukayna and Shuya Toriyama at the same time, who are both considered masters.

Immense Strength: William has incredible physical strength. He can deal incredible amounts of damage to his opponents with mere punches, and deal even more damage by enhancing his attacks with his Dragon Slayer Magic. He can also lift incredibly heavy stones, even those of gigantic proportions, such as the size of small mountains. His strength was enough to cause Reed Yuriko to cough up blood by punching and kicking him with spells enhanced by his Cavern Dragon Slayer Magic, throw Hino Sontara from the middle of Deltra City to the Eastern Forest with one hand and aid from his Gale Dragon Slayer Magic, stop one of his Dragon Slayer spells with one earth-covered hand, latching onto his body with enough force that he couldn't escape, and even match Hino's Secret Art with the aid of his Gale Dragon's Wind Step, and Cavern Dragon's Mountain Armor temporarily.

Immense Speed: William is capable of moving at incredible speeds. He's fast enough to avoid attacks made by Seraph Kinmichi, and briefly outmaneuver Hyperion Lucis. He can increase his speed further by using his Gale Dragon Slayer Magic, and his speed underground is considered unrivaled. He was fast enough to outpace Reed Yuriko, and easily block his attacks. With assistance from his Gale Dragon Slayer Magic Reed was completely unable to match him in speed, while using his Cavern Dragon Slayer Magic he was able to tunnel in the earth so fast that he moved from the bottom of his Dragon's Den to the top in order to deal a devastating combination assault. Against Amunet Fukayna and Shuya Toriyama, he proved fast enough to catch both of them off guard with his Gale Dragon’s Cataclysm, and completely outpaced them in combat. He even managed to avoid attacks made by Hino Sontara's Lighting Dragon Slayer Magic, with the aid of his own Gale Dragon Slayer Magic.

Immense Durability: As a byproduct of William's Cavern Dragon Slayer Magic, he is capable of taking immense amounts of punishment. His body's durable stems from his Dragon Slayer immunity to earth-based attacks (with the exception of Earth God Slayer Magic and similar God Slayer magics). His body can withstand any amount of pressure from earth, and this affects his resistance to normal attacks as well. William was able to withstand attacks from Seraph Kinmichi, and torture from Cronus Saturnalia without breaking. He also took a head butt from Reed Yuriko that only caused him minor discomfort, without using any magical protection at all, and dealt a counterattack immediately afterwards. He even managed to withstand Hino Sontara's Dragon Slayer's Secret Art, which sent him hurtling into the ground and left a giant crater, with the aid of his Gale Dragon's Wind Step, and Cavern Dragon's Mountain Armor. He then proceeded to rise to his feet, and counterattack with his own Secret Art.

Immense Magical Power: William has a high amount of magical power. He's powerful enough to sustain a weaker variation of the Flame of Rebuke, without completely draining his magical power for several minutes, and fight evenly with Seraph Kinmichi. He even managed to kill Cadmus Zephyrus, someone who fought evenly with Aether Cade in the past. He even completely outmatched Reed Yuriko in combat, one of the strongest mages in Warrior Angel, who was chosen to represent the guild during the X800 Grand Magic Games, and outmatched both Shuya Toriyama and Amunet Fukayna of Sorrow Ocean during his tag team battle with Sykushi Strykri, even opting to fight them both on his own, overpowering them and forcing them to surrender. The power of his aura alone was enough to shake the ground and intimidate Spirit and causing him to state he was on a different level from Hino Sontara, as well as overpower said Dragon Slayer in the early stages of their battle. When exerting his magical aura it is colored yellow when using his Cavern Dragon Slayer Magic, and green when using his Gale Dragon Slayer Magic. When using both, it appears as a yellow aura surrounded by a larger green aura.

Dragon Gunfire
Aether Cade: William's guild master, and the one that William holds more respect for than anyone else he knows. During the Dragon Gunfire Civil War, William sided with Aether's faction, believing wholeheartedly that Dragon Slayers were not superior to other humans. After the war, upon request from Aether, William began tracking Othrys activity. In return, after William was captured by Othrys, Aether started the Dragon Gunfire-Othrys War in order to rescue him.

Chase Grimsted: Chase is not very fond of William. He believes that William can never understand the pain he endured, and that William's pain was comparatively a scratch. William, however, respects Chase, and even believes that he is stronger than him, thinking that he is stronger emotionally, and physically. The two were partnered during Dragon Gunfire's S-Class Promotional Trial, and Chase, along with Miriam Cade, rescued him from Othrys.

Othrys
Cronus Saturnalia: Cronus is the King of Othrys. Initially, William had no opinion of Cronus. Despite being kidnapped and tortured by him, William never hated him. But after the Grand Magic Games second trial causing him to see his ultimate fear of loss, at the hands of Cronus, he began to despise him. He can never trust Cronus, no matter the circumstance, and believes that as long as Cronus is alive, his vision can become true.

Trivia
In Roman Mythology, Mercury is the Roman Messenger of the Gods, notable for his incredible speed. Mercury was also born and raised in a cave. This is similar to William due to his incredible speed due to his Gale Dragon Slayer Magic, and his Cavern Dragon Slayer Magic's overall abilities and title.

William's appearance is based off of Archer from Fate/Unlimited Blade Works.

William has undergone two different changes in magic abilities. At first he was a master Fire Mage, then used a magic called Typhon, and is now a Dragon Slayer.

William's stats are: