Nightmare is the most powerful being in the Omni verse, he's perfect skeleton that possessess extreme God like Abilities, like Kamehamehas, Infinite Immortal Techniques, and many more, he also possessess high intelligence and battle intelligence, due to him being 540 Centillion Years old, Nightmare wears a black cap, black hoodie, and black slacks, Nightmare is cold and doesn't like to talk, he is Extremely violent and aggressive, while also being Relentless.