Quote Originally Posted by noob View Post
I think the only legitimate demon or devil disposal is converting them to good.
If that is not possible then it is cruel to kill them, dangerous to just let them leave and dangerous too to try to trap them forever.
So the issue of disposing of them is probably unmanageable.
(Emphasis mine)

I assume the popularity and assumption of the "redeemed fiend" is part of the influence of Planescape (especially Torment with Fall-From-Grace being a party member). In all the settings I've enjoyed most (and all the ones I've made), fiends are just physical manifestations of primordial evil; they're literally incapable of doing good without being forced into it, and destroying them amounts to removing a chunk of purely malicious energy from the cosmos.

Mind you, in that case, I think enslaving or compelling them instead of destroying them is mildly evil. My calculus is that it's an evil act (enslavement of a sentient being), performed for a neutral cause (advancing the cause on one's nation), with a minor incidental good effect (very slightly weakening the forces of evil). A nation would have to be pretty darn Good outside of this practice to balance out even on the Good side of Neutral.