So what do you think ever happened to Aldernon and Calenhad? I realize that they are supposed to be a Merlin and King Arthur like characters but for such a influential character like Aldernon just disappearing feels unfilling. Especially when Calenhad had TWO stories of his life shared as told by Fereldens and the Qunari.
Okay but like if anyone reading this is confused: @newwillinium is right in this totally being a Merlin and King Arthur story, and also Aldernon is just a real badass, he was basically a proto-Anders. You can read the whole thing across these codex entries:
Codex entry: Aldenon's Vestments
Codex entry: Freedom's Promise
Codex entry: Wisdom's Eye
Codex entry: Robes of the Pretender
Anyway, to answer your question, the ending of the last codex entry has me imagining Calenhad finding Aldernon, professing his deepest regrets, and the two making amends. The fact that Calenhad was never seen again has me less convinced he just disappeared--especially given if you take the Qunari tales into account, that he was no normal man--but rather, maybe he and Aldernon decided to abandon everything and live out the rest of their lives on a beach somewhere or something.