Being off-topic here is not a problem, we'll answer pretty much anything. I just wanted to make sure that this wasn't a Valen-specific bug I should look into.
The fact that you can use Disintegrate on the Empathic Manifestation is probably a bug. As the dialogue suggests, you should use Healing spells on him.
Just to make sure we're all on the same page: you're not trying to report a Valen bug here, right? You're just talking about SoA?
u noe the quest where theres this lost city underground and the peepl r like dieased or something in SoA.. well theres the temple rite.. and u go in and theres a demon which says 'kill me' or something.. so i do.. but when i killed him nuthin else happens..!! i started off with my fighters gettin him down to near death but he won die!! so then i used my mage with 'disentagrate' and at last turns him into dust.. but then nuthin else happens..