Honestly, most of Everfire's "evil" characters are lackluster as far as I am concerned, so I wasn't shocked that the story ended in such an absurd way. I think only the evil Indian Mother story worked for me because she had an understandable motivation beyond, "because I'm evil" or "because it's fun to do bad things".
Honestly, Everfire is at their best when they focus on unrestrained desires (love, revenge, lust, etc.) guiding characters down a path of bestiality, incest or just corruption.