Is this a Zombie?

Ayumu Aikawa's ordinary high school life ends when a serial killer murders him. He returns anyway after necromancer Eucliwood Hellscythe revives him as a zombie, and Ayumu begins serving as her guard.

His supernatural problems multiply when he accidentally takes the magical power of Haruna, a mahou shoujo. Unable to fight as she normally would, Haruna orders Ayumu to take her place against creatures known as Megalo. The result leaves a formerly normal student balancing life as an undead bodyguard with an unwanted magical role in a conflict he was never supposed to join.