: if he wasn't supposed to win, then why did he win?
2 reasons. First, Alric and The Head figured out lots of clever ways to get rid of the Fallen Lords one by one. Second, Balor linked the lesser Fallen to himself so that they were destroyed or weakened by his death.
Now the cycle had proceeded normally, Alric would have killed Balor, but the remaining Dark forces would have killed him and finished off the few Light soldiers left; and the Dark would have reigned for a thousand years. But because of the 2 reasons given above, after Balor died there were virtually no Dark forces left. So Alric survived and the Light triumphed.
--SiliconDream