Watched "Silence of the Slams" from Grimm. A young wrestler commissions a mask maker to produce a mask that will render him an all-time winner. The mask maker kills a Wesen and cuts off his face a la Hannibal Lecter and fashions a magical mask out of it. He gives it to the wrestler, provided that he is paid 50% of the wrestler's winnings and that he should return the mask once he is done with it. He also warns the wrestler not to wear the mask outside the ring.

The wrestler wins a match against the reigning champion. However, the champion accosts him in an alley and the wrestler is compelled to put on the mask, defend himself, and kill the defeated champion. When he gets home he is unable to take off the mask. He goes back to the mask maker,
who is unable to help him, and kills the mask maker as the Wesen spirit completely takes over him. Nick and Hank arrive in time to pin the wrestler down. Rosalee and Monroe perform a ritual that effectively takes off the mask.

This episode takes on a Curious Goods in Friday the 13th quality and seems to be merely the subplot against which the healing-stick, Hadrian's-Wall-versus-Black-Claw, and Adalind-is-a-Hexenbiest-again story threads are made to advance.

I'm also wondering how Nick and Hank are able to pin down the wrestler, considering that he is wearing a magical mask.