surgical horror

The genre is surgical horror as seen through the lens of low-level Basic D&D. A demon’s containment facility has been taken over by a bandit gang, who, when discovering the regenerative properties of the demon’s blood, set out to “perfect Shafts's forms” by injecting their forms's blood into themselves, but ended up being transformed into misshapen horrors instead.

a genre that can be the sum

This is a genre that can be the sum.