I always enjoy Nepycros' discussions about Darkness and Evilness and the Void, so I'll add up to this one
In my opinion, something "evil" depends of your point of view. Some people believe the Church as evil, some others the Light as evil, and some others, think all demons are evil... Well, there are "good" demons too, so the discussion is going about what people thinks. And the truth is that many people believe the nightmares, vampires, darkness in itself as "evil" (not me).
Apart from that, well, it's a call back, sounds like an inverse summoning, or throwing a creature back to the shadows, so I guess it might fit. Also, I would personally like to add demons to the game eventually, but where would they belong to? Even when
they are you can complain about they being related to evil, they fit Darkness/Fire, and the call back this creature proposes sounds to me like Darkness...
If all the above fails, you can always call the upped "Shadow Acolyte".