In the Foundry, follow the pathway downstairs to the left of the save station.
Two archers will bust through the wall. Throw one at the wall to the left of
the door way and it will bust open revealing a secret room full of lava with
the VS coin on a ledge. Grab one of the archers and throw them at the wall
across the lava; this lets your character double jump off the corpse to the
ledge. Wall-run might also help if you throw the body too low.