Shadow Conjuration vs. Regeneration

[Achilles]

So, a troll thinks it takes Shadow Conjuration fireball damage. Since the thing is not truly burned, does its regen help it? Can it come back from the dead after hitting negatives due to its mind no longer being fooled?

[Blave]

The troll IS in fact burned. 20% of the damage is real fire damage. So the regeneration won't work.

[CBDunkerson]

My view has always been that 'shadow illusions' are 'fully real' to targets that do not disbelieve and 'partly real' even to those that do disbelieve. So yeah... that troll has taken 'real' fire damage. Even if it disbelieved it would have taken fire damage... just less of it.