Unalaq was in my opinion, the series’ worst major villain. An opinion I apparently share with a lot of fans.
He’s actually Korra’s uncle and he somehow became the leader of the water tribes. He’s also the father of those two weird twins.
And when weird spirits come out of nowhere and wreak havoc, he seems to be one of the few that knows how to handle them.
But it turned out he was actually working for the dark evil spirit that’s the counterpart of the light spirit that helped create the original Avatar.
And he becomes the first and only Dark Avatar. He kind of looks like a Power Rangers villain but he definitely gave Korra a run for her money.
But she eventually manages to defeat him. I was glad we never had to see him ever again.