Magneto was made using a Grim Reaper body, sentry arms (grim reaper shoulder joint was heavily modified to allow for this), Superior Venom Hands, a cast of a Magneto head (not quite sure which head it is though), a cast of the hood from the BAF hobgoblin, a belt from Marvel Now Cyclops (modified) and an Odin BAF cape.
I did all my sculpting using apoxie sculpt. I beefed up the shoulders to accommodate the new bigger arms. I also sculpted the gloves on the lower arms, details on the helmet, knee pads, the front of the cape, the bands around the shoulders, the grey part on the sides of the costume and the front of the belt.

Thanks for looking!