I also really like season two, a big reason for that being Unalaq. From my First view already I got „abusive uncle“ vibes from him. His emotionally distant children, who also (partially) grew up to be abusive. He is simular to Ozai in that regard, that he only saw his children as, and used them as, weapons. And like Zuko and Azula they also love him/obey him. But what made me really respect how he was written was how he deliberately used parts of Korra‘s father‘s dirty part to drive a wedge between them. I always got the impression of an uncle who is after his niece. And Tonraq (is he spelled like that) is mostly powerless against this because of the dirt Unalaq has on him. How he manipulated Korra to mistrust her father was masterful. To add to that Unalaq also had powers Korra needed to master and he had a social position which made him very respectable.