I have been thinking about my incident with Fane a lot in the past few days. I can't even progress through the game, I just kept thinking about it. So today I made a decision, I'm going to put him back on the party through Persuasion. Normally I wouldn't do it; but after reading Raze's response, saying that the developers of the game even already launched a patch trying to fix this issue... I think I can forgive both myself and the developers for the incident with Aetera, at the Ancient Temple.
This whole thing is really an exceptional situation, so I'm going to use an exceptional fix. Just gonna make a visit to our dearest friend, Mr. MAGIC MIRROR, get some Persuasion points, put Fane on the party, and then remove the Persuasion points. Problem solved, right? I had already finished the Academy quests, but they are not too many, I can redo them with Fane in a couple hours.
I can't abandon Fane right when he is about to shine.