system
Given the following post, respond as if you're commenting on Reddit:
human
[Avatar: TLA and LoK] Are avatars always good?

My experience with Avatar amounts to whatever I could catch on-air back in middle school and the first season of Korra, so pardon me if this is a stupid question.

Whenever an avatar, past or present, they're usually portrayed as heroic and selfless: Aang fights tyrants and invaders, Korra fights criminals and terrorists, etc. Even Kiyoshi, though willing to kill, sought to keep the peace. They risk their lives to fight oppressors and protect the weak; they're "good."

We've never seen an avatar who is self-serving or who uses their powers for their own benefit at the cost of others. The different nations could always kill an avatar who made a power-play against them, but we've never even heard of an avatar like that.

Are they born with selfless traits necessarily? Would an avatar who acted "evil" lose their powers?
gpt
It's the same person reincarnated over and over again, so yes, they are all good at the core. In the later seasons of TLOK, you can see how similar Korra is to Aang; deep down they both share the same traits of compassion and empathy.

Avatars however are still part human. They can struggle and make mistakes. They can misjudge or act in error. Their hearts, however, are always in the right place.

Plus it helps that the spirit part of the Avatar is Raava, the Spirit of Light.