Lobo is one of Zero's Beast souls that takes the form of a large jet-black werewolf. This form actually increases Zero's size and weight slightly as this massive beast has a large build of mostly muscle. While Zero keeps his full mentality of his human form, this beast soul adds somewhat of a feral touch. Letting his wild instincts act more aggressively. Which results in heightened senses, increased reaction time and most deadly of all a boost to his speed and strength to unbelievable heights. It is also do to his feral nature, that this form releases a massive blood lust when first released. So much so, that everyone around him, during his transformation will feel it and sometimes freeze in place. This beast stands tall on two legs, though with a slight hunch. While the Jet-black werewolf form is the base, Lobo can also take on a form of a black flamed werewolf, which is when Zero's flames engulf his whole body for added speed, power and defense.
Keen Senses and Increased Strength: Lobo gives Zero heightened senses like increasing his hearing up to four times to that of humans. Allowing Zero to hear conversations from a long distance as well as stay alert for anything that might head his way giving him an edge to either avoid or ambush certain targets. This can even be increased to the point of hearing a persons subtle breath when chasing his targets. Zero's sight is also heightened to be able to see over a long distance as well as improved night vision making the dark a powerful ally. Lobo's sense of smell is powerful enough to rival that of slayers or may in fact be slightly better. Lobo can pick up scents from miles away as well as distinguish each smell. Allowing for an improved chance of chasing the right target. Even in crowded areas, Lobo can take in all the scents and distinguish them to find the appropriate target. This also helps in finding when things may be poisoned or altered in someway. Lobo's strength is yet another incredible asset, as he can lift objects several times his own weight and launch them over long distances. He can easily break apart a steel door, launch boulders several meters, even rip the ground apart and lift large portions of it with ease. The force behind each hit feels like being pounded by large hammers.
Immense Speed: Lobo has the speed to move around so fast, that most of his opponents only see a black blur. Though that is not the limit to his speed, as Lobo can get even faster with the help of his Black Fire Magic, which will increase his speed further to the point it seems like teleportation rather then running or jumping around. While there are many mages fast enough to keep up, Lobo's speed is still one of the more deadly aspects of this transformation.
Steel Skin: Do to the amount of muscle mass that Lobo grants Zero, it serves to be quite and astounding defense. Normal weapons are unable to pierce his thick muscles that seem a few times stronger than steel. It takes hits with large amounts of magic behind them to cause major damage.
Healing Factor: Lobo possess the ability to heal or regenerate at a much faster rate. Though he is not able to regrow lost limbs, he can heal cuts, bruises, broken bones or pierced flesh at such a fast pace that it will not affect him in battle. Though this does require a decent amount of magic.
While in Lobo form, Zero is still fully capable of using all his different types of magic, which also resulted in his beast form having a flame mode. Which allows the whole body to be covered in his black flames. Though in this form Zero has been able to create new unique spells and attacks based of the transformation.
- Flaming Roll (フレーミングロールFurēmingurōru): Lobo engulfs his body in a dense black fire that will severely any and all who get hit by it. He then proceeds to curl up like a ball and actually launch himself forward using his fire as a thruster. It basically looks like a giant black fire ball. He can traverse through the air or ground and even go through walls and continue his charge. He is able to stop or start his roll at anytime and the flame surrounding him is strong enough to block many attacks. He can also take this spell even further and create up to five copies of the black fire balls to surround him and attack the target(s). This spell he calls Stampede(スタンピードSutanpīdo). The giant flaming fire balls will not dissipate until destroyed, dispelled by a mage or Zero himself.
- Black Howl (ブラックハウルBurakkuhauru): By letting out a ferocious Howl. A large shockwave of black fire is released from his whole body enveloping the surroundings in powerful black flames.
- Fire Claw (ファイアークローFaiākurō): This spell has many uses, though it's main one is slashing at his opponents not only cutting them, but burning them greatly. Do to the fact that every time Zero slashes with his Fire Claw, a stream of black fire follows the slash, it can be used as a powerful shield to block incoming attacks. Depending on how he goes about his slashing, the streams of fire can be used in many other ways as well, especially when used with his Rainbow Fire as the streams will have different affects depending on the flames. Lobo can also launch this spell, first by slashing both arms in a diagonal manner creating a cross, then proceeding to slash both arms horizontally causing the stream to be at the center of the cross, which also causes the cross to fly forward at high speeds, exploding when making contact with an object or person. This spell known as Sabrewolf(サーベル狼SāberuŌkami).