Avy has died twice, both times I sacrifced him to progress the game and to stop power creep. As am the mod on NF I have no issues sacrificing characters for the good of the game. I only power creep to match the others, but still have no issues killing my own for the game.

Avy and Berserker vs Moses
Avy and Archer vs The Elder Dragon

Were when Avy died, firstly an Empathy spell that killed both he and Moses
Secondly he used all his mana since he was a spirit puppet to kill the dragon, and thus died.