The Thing Under the Drawing Room

As part of a contest, a barbarian permits himself to be possessed by a god.

"He had slain wizards. He had collapsed gates through which the old ones sought reentry to our roads, our cities, our hearths. He had cut down beasts born of the necromantic arts, some grown from flesh and bone, others crafted with cog and spring. The Sundering Game was a simple affair by comparison. Gotchimus would be possessed by the spirit of an old god. The god might kill its mortal host, and it might drive him mad—or Gotchimus would drive it off before it could do either."