Monster Soul

From wikipedia:

The tale of Monster Soul takes place in the land of Elfenland where humans and monsters inhabit. The main characters is a group of monsters called the Black Airs. The Black Airs is recorded as the strongest group of the monster forces in the great war between the humans and monsters.

Creator: MASHIMA Hiro
Length: 2 volumes
Scanlation Status: Ongoing
Genre: Action, Adventure, Comedy, Fantasy, Shounen