No, he can be found alive on the Nameless Isle, and you can bring him to the elven temple. Apparently there is either a time or quest trigger that he dies if certain conditions are met, or opponents near there wandered too close.
Sorry. I wasn't clear. I already did all of that. After Alexander gave me all the info on the Lunar Temple, he, Delorus, and the other magisters and paladins left presumably for the Lunar Temple. I headed straight there and just north of the temple, found a dead Delorus and the four dead Black Ring members. No sign of the other magisters/paladins and Alexander was inside of course.
