This is really frustrating. Some people may not like Korra as a character,sure,but for the love of god please don't say she is a mary sue. This term is now just a term used to describe any unlikeable female character. Korra is extremely flawed, we see this right in the first episode, and her personality is polarising within the series. Other characters frequently criticise and doubt her. I personally love Korra so much, I think she was a much more engaging protagonist, and yet I see why some might dislike her. However, calling her a Mary Sue is a dead giveaway that you don't know what you're talking about. She trained like 14 years. Not to mention the amount of suffering she endures, the world leaders and the citisens who don’t give a shit about her, as well as the fact that literally in the first episode of the entire series Lin basically says “I don’t care that you’re the Avatar you have to obey the law regardless” on top of her numerous defeats in both combat and ideology throughout the entire series.