Tenebrae
He is a Centurion Spirit of Ratatosk that is attuned to the element of darkness. He appears before Emil, and they agree to a contract that turns him into a Knight of Ratatosk.

Although Tenebrae came from another world, he has lost much of his power since then, rendering him unable to return to his home. He is very calm, composed, and serious, although is is known to make the occasional joke. He is extremely loyal to Marta Lualdi, who is carrying the Ratatosk Core on her forehead.