ToME: the Tales of Maj'Eyal

I died on the turn where the final blow fell on Ziguranth.
I unlocked Corruptor.
I get to pick a party member to learn the hexes generic talent tree... but they're all dead (that is, I am dead). I'm stuck.

After a forced close on the game, I lost out on the talent tree (but kept the Corruptor unlock and the Anti-Antimagic achievement)

Were you using an Alchemist, with your Golem surviving after you died?

Archmage.
The grand corruptor was the only other non-hostile creature around.