Shin

Fanart of Shin from the manga Dorohedoro.

Shin's mask is shaped like a human heart, although he usually wears it backwards with the front of it facing backwards and two eye holes cut out of the back.
His tool of choice is a hammer, as well as his magic smoke that allows him to dismember and dissect people without them physically dying.
Despite being a hitman Shin believes in fair fighting and refuses to use his magic abillity's on people who cannot use magic, resorting to his hammer instead.