I realized something today while replaying the battle with Miraak, he was indirectly responsible for the entire main questline of Skyrim. During the battle Miraak says "They wanted to use me to deal with Alduin - http://elderscrolls.wikia.com/wiki/Hakon_One-Eye and the rest. I chose otherwise." As I interpreted it that meant the Miraak was the Dragonborn who was destined to kill Alduin in the Merethic Order, but simply refused to do so. His refusal forced the Nordic heroes to instead use the Elder Scroll to send Alduin forward in time, where Alduin began the Dragon Crisis (main plot of vanilla Skyrim) in the 4th era. If Miraak had accepted his destiny and killed Alduin like he was supposed to, then the PC wouldn't have become the Dragonborn who would eventually kill him (with some help from Herma-Mora.) Just thought that was interesting...

Do you think he refused to kill Alduin before becoming Mora's champion? Due to his worship of the dragons (and in turn, Alduin) he did not fulfill his role. I really hope we get clarification on how this all went down.

He would have failed to defeat Alduin anyway. The Last Dragonborn was destined to kill Alduin in the Prophecy. Miraak was defeated by the Dragons at his temple, and that was after worshipping them and learning their power.

Was Mirage beaten by Vahlok? He was sent to Herma-Mora before he was killed.

Mirage, funny.