Sora

Sora (空) is the most powerful name in the Kuroninja Multiverse. It is special because anyone named Sora can win against Kuroninja, which breaks one of the most important rules of the Kuroninja Multiverse: ''Kuroninja always wins. ''

Because of this, not a lot of characters in the Kuroninja Multiverse are named Sora. Otherwise, they would be able to win against Kuroninja.

There is a theory that Kuroninja's real name is Sora, but it's very unlikely to be true.