I'm still trying to figure out why she's a legend. She's just a big fuck up of an avatar really, and she's suffering because of her mistakes.
What are you even talking about...? She's a legend for one, because she made the decision to leave the spirit portals open connecting humans and spirits together in a way that hadn't been the case since the era of Wan, and in the process she brought back an entire nation of people from the brink of extinction... All the Avatars made mistakes. It's what made them human, rather then some omniscient beings.
I suppose you're right. We'll see how she deals with Kuvira!