Dr. Doom vs Ahriman from the Warhammer 40k universe. I'm sure most of you know who Doom is, but Ahriman is one of the most powerful psyker/sorcerers of WH40k. They are both incredibly strong, masters of magic and have power armor. I've gone with the Earth-616 version of Doom, right after his return from 'hell'. I'm estimating Doom's strength around the 20 ton mark since he fought Luke Cage to a standstill.
Right now Doom is losing the battle, if anyone has any information that can help Doom, please speak up.