User blog comment:Crimson and Darkness/Volume 24 discussion blog/@comment-185.112.105.215-20171110041824/@comment-120.188.5.139-20171110164055

They do exist in DxD world and so do Dwarf. In Vol 7 it was revealed everytime Midgardsorm wakes up and goes to the surface, the Dark Elves will take care of him and it was the Dwarf as i recall who managed to make a replica of Mjolnir.

Maybe they will be revealed more in the spin off or sequel