Kanna (AIR)

Kanna-bi no Mikoto, most known as Kanna, is a key character in the visual novel AIR, and the true final boss of the game Eternal Fighter Zero.

AIR
She lived back in the 10th century, and was one of the last of the winged race in history. Because of the awesome power inherent in all their kind, Kanna was revered as a god, and isolated from the populace out of fear. Despite being moved from temple to temple constantly throughout her life, Kanna was eventually able to became close friends with 2 of her followers, the servant Uraha and the lieutenant Ryuuya. During AIR, Kanna escapes her temple with Uraha and Ryuuya and goes on a long and arduous journey in order to find her mother, with all of Japan searching for her...

Eternal Fighter Zero
In Eternal Fighter Zero, if the player manages to get to stage 8 without using continues, he will fight Kanna, for she is the true final boss of the game. She is insanely powerful and uses her divine attacks to crush her opponents. Differently than UNKNOWN, her boss-version has no difference from her playable version, making her an unbalanced character, much stronger than any other in the game, this makes her be constantly banned from tournament play.