Nightmare

Abilities
Beyond comprehension. He is practically the upper limit of power, able to devour even the strongest of Gods, turn over planets, etc. Normally, however, he appears as a harmless (if psychopathic-seeming) little boy, usually wearing bloodstained clothes.

Although most would label his power as a form of reality modification (since he's able to turn the environment around him into something nightmarish and deadly) mixed with body modification (since he's able to shapeshift, and even create weapons from his own body), the true fact is that the small form of a child he normally takes is at best an avatar of his true shape - a planet filled with the most lethal environments imaginable, able to defy physics to this end.

He rarely uses his full abilities, however, as most mortals and even most immortals aren't even worth killing or even fighting - his avatar is durable enough to be near immortal, and even if it is somehow slain, it's just an avatar, a small, meaningless sample of its true form.

In other words, it's the Outer God that eats other Outer Gods. Thanks to this nature, however, it finds Crossroad's High detestful to stay around, since the school has been well warded against such eldritch abominations.