If they die in this manner, they're gone for good. Just like if you fight and kill them. I killed Sebille in my current playthrough. If you don't see their "spirit" hovering over their corpse, you can't target them with Resurrection. If they're not in your party, then they're just like any other neutral NPC - you can't resurrect them.

Last edited by Try2Handing; 20/09/18 09:46 AM.
"We make our choices and take what comes and the rest is void."