Battle Mode Shift

Battle Mode Shift (戦闘モードシフト, Sentō Mōdo Shifuto) is a Caster-type Magic exclusive to the Exceed race, though isn't accessible by the entire race.

Description
Battle Mode Shift allows an Exceed to enter their "Battle Mode" (戦闘モード, Sentō Mōdo), an enlarged, typically bulkier and more powerful version of themselves, typically the size of a full grown adult or larger. In this form, an Exceed becomes more fitted for combat, gaining a boost to all of their abilities, physical and magical. Their Aera also enhances, becoming full-fledged, large wings, capable of causing gales of wind, and even functioning as efficient defenses against attacks. Notably, the Battle Mode may vary in appearance from the Exceed's original form, depending on said Exceed's expertise in its employment. An Exceed accesses their Battle Mode by "opening" their magic origin, allowing great amounts of magic power to pour from their core throughout their entire body, causing an "overflow" which triggers the growth effect that transforms an Exceed into their Battle Mode. Typically, the form lasts for a rough amount of time, but further practice can allow it to last for much longer the more an Exceed trains.

However, Battle Mode Shift isn't accessible to all Exceeds. While all Exceeds do have the potential to use it, only those who actually manage to "open" their magic origin and allow their magic power to pour out without hurting them are the ones who manage to access the form, while others simply end up damaging their own bodies while trying. As such, while all Exceeds possess it deep within their body, not all are capable of unlocking it. In addition, Exceed tend to lose their ability to enter Battle Mode after reaching a certain age, or after mating and having offsprings, due to a large part of their magic power being "donated" to the Egg, this includes all the parent Exceeds from Extalia, but also means all the Exceeds on Earth Land have the potential to access Battle Mode still.

Vicious Character Shift
Vicious Character Shift (鋒鋩交代, Hōbō Kōtai lit. The Tip of an Edged Instrument Alternation) is considered to be a much "dark" equivlant of Battle Mode Shift. Typically, an Exceed accesses their Battle Mode by simply "opening" their magic power willingly. However, there exists an alternate way to do so, but it is considered more dangerous, both to the user and everyone else. It is most common among the Exceed who fail to access Battle Mode who push themselves too hard. Vicious Character Shift occurs once an Exceed is fueled by their negative and dark emotions, anything ranging from simple greed, to absolute hate and anger, which corrupts their magic origin only temporarily, with no real significant harm to them. However, if they attempt to access Battle Mode at that state, and haven't done so ever before, they unlock the Vicious Character Shift instead, becoming a monstrous, demonic version of themselves, barely resembling a cat anymore. Once this happens, the Exceed cannot revert back until they have either lost consciousness or completely run dry of their magic power, forcing them to revert back to normal. In addition, their personality becomes more feral and vicious compared to before, being fueled by their worse traits and emotions.

Vicious Character Shift immediately overtakes the Battle Mode Shift, making it impossible for the Exceed to ever hope to achieve the normal Battle Mode, their only option becoming a monstrous form that can potentially cause them to harm their friends and allies, as well as run out of magic power in a matter of minutes if reckless. Aera is also affected during Vicious Character Shift, the angelic wings turning demonic instead, or simply scaley, compared to before.

Whether Vicious Character Shift or the normal Battle Mode is stronger is arguable, since the forms power is dependent on the user's own skill and power.

Trivia

 * There was no real reason to make this, the author was simply bored and felt this would make things somewhat easier atleast.