Massacre

Massacre (虐殺 Gyakusatsu) is a Curse that involves empowerement.

Description
A curse which empowers the user following them killing another person and has been described simply as "bloodlust". By killing, the user's own strength and speed are increased dramatically although as a side effect: the user develops a "hunger" in which when confronted with a battle, they are overwhelmed with the urge to kill.