Character: Black Pawn
Concept: skeleton (duh)
Animating skeletons are cakewalk for the demon king and therefore able to supplement forces fairly easily.
Promoting the black pawn involves dark magic evolving the skeleton, transforming body parts to suit needs. May transform the whole appearance.
//Skeletons are so much hassle to draw, especially the rib cage, and theres so many parts. I have 4 more skeletons to go for the promoted pawns, and the incorporate different animal skeletons. wow.