Mashup of Fyndhorn Brownie and Skull Fracture. Fairly straightforward.

Hmm. I like how discarding is a cost here, because it does help a non-black ability feel more black. It's still... a non-black ability. I've made arguments for putting untap in red, so that would feel right to me. I could also dig discard to untap in blue... discard as a cost doesn't seem too out of place in that color. Black, though, often gets flavored with entropy and sapping energy away, while untapping is often flavored with envigorating with energy. Odd mix.