>>116667506She was able to resist bloodbending without the Avatar State and then beat Amon on her own. She was also able to connect with the inner workings of universe and fight toe-to-toe with the literal embodiment of Chaos after losing her status as the Avatar and all of the power that comes with it.
Then there's the whole mercury poisoning event that almost took her life and the ability to bend pure energy into dimensional bridges while not having access to all of the knowledge and experience of previous Avatars.
The most powerful thing that Aang ever did was bending energy to take away people's bending or return it to them. Korra is ridiculously overpowered in comparison and requiring some help here and there doesn't change that.
Especially when you're reminded that Aang required a lot of help himself.
