This is Kurokishi, a female fighter who appears in the Guardians game called denjin makai 2, a Japanese game.
The appearance is completely different from the previous work, but first of all, the appearance of the Denjin makai is purple hair and the outfit suits the name of the black knight (?) All black, but after moving to the Guardians, he wears a red jacket, skirt, and white tank top with a blonde ponytail. That's why he doesn't look like a black knight at all. A look reminiscent of a certain blonde ponytail from Banpresto .