User blog comment:ND999/Lore Hypothesis, Mt. Targon, Guardian Sea and Shadow Isles/@comment-3087008-20141115152137

I am going to take it one step furthur and say that Kalista was the previous avatar of the moon. She was betrayed by those she trusted the most, the Sun Avatar, and is consumed by the desire for revenge, just like how Diana was betrayed by the solari and seeks vengeance.