Unfortunately, this is a fail for Gale's story. The bomb in his chest was supposed to be Gale's curse for encroaching on Mystra's place. His original storyline was similar to Astarion's in that he always wanted to be a God. Then that got cut out, with the description on the website being changed right for the game's release.
All of the stories could have been more in-depth, but each one was softened. Now he's just a "good mage who wanted to please the goddess". But he was supposed to be the prototype for the new Karsus.
After that, I'm even more eager to help Gale get the Crown of Karsus. After all, if Astarion has his Ascension and his beloved in my story, then Gale should have something too, right? Let him get what he deserves too.
