Sebastian LaCroix

Undead Monarch
The Los Angeles prince of vampires, a figure of power in the world of vampires.

Season 3
He has heard a powerful person known to not believe in magic has appeared in the ring and LaCroix has had the idea to transform him into his subordinate. However, that didn't turn out too well...

Season 6
His vampire powers had him able to survive the apocalypse.

Episode 8

Comes back in TFR Underground in order to join BANS Army.

Probably got his neck snapped by Kido Reiji though.