Viktyr Gehrig
First Post
Animate the corpse and throw it off the edge of Sigil. If I recall correctly, not even wish level magic can return someone or something from that particular Void.
Styxing him before killing him should help, too-- it'll make him less likely to willingly accept resurrection from his allies. If you can catch him alive and mostly incapacitated, I think you can use mindwipe and psychic chirurgery to make him irreparably and utterly useless to his allies-- no sense bringing him back if he doesn't remember anything and can't do anything.
Styxing him before killing him should help, too-- it'll make him less likely to willingly accept resurrection from his allies. If you can catch him alive and mostly incapacitated, I think you can use mindwipe and psychic chirurgery to make him irreparably and utterly useless to his allies-- no sense bringing him back if he doesn't remember anything and can't do anything.