Bad souls are used as primal source for devils. Good souls become bricks in the wall of heaven. Sooner or later, all of them are distilled back into material plane. Nobody enjoys an eternal afterlife of joy (or suffering)
I'd suggest an Assassin investing in a sufficient sized Null Space Chamber. They kill the target, take what they need to verify the kill, then chuck the corpse into an NSC, then chuck a grenade in there and close the NSC. Grenade goes boom, wrecks the NSC and makes the body unrecoverable.
Nobody enjoys an eternal afterlife of joy (or suffering)
No one who's died has ever told me that. The next time I run into one, I'll ask them ;)