Diirinka

Diirinka was the god of the derro, monstrous hybrids of dwarves and humans that inhabited the Underdark.

His symbol was a spiral of gray, black, and white.

He was a deity of magic and knowledge, as well as cruelty. He resided in the realm called the Hidden Betrayal on Pandemonium's layer of Phlegethon.

It should be noted that Diirinka might not exist, as the truth behind the Derro's origins was that they were a form of dwarves tortured into insanity by the illithids.