Yangchen is what the fandom think Kyoshi is like
Minor Yangchen books spoilers ahead.
Burdened by an extremely “active” avatar state, she was frequently haunted by the memories of past avatars, even avatars that lived thousands of years before her, from a very young age.
Because she experienced vividly every previous avatar’s life, she quickly realised that her predecessors mostly regretted not being decisive or not acting exactly in the moment they needed to act. (Hindsight is 20/20)
She was an absolutely brutal airbender, she frequently asphyxiated people, blew their eardrums, and even used infrasonic waves to torture people and interrogate them for information. She was hardly a pacifist.
She even turned the western air temple into a prison and airnomads into jailors. Eventually getting excommunicated and banished from the temple as a result.
With all of that said, she basically transformed the world, and her legacy is that of peace, development and progress. She is the GOAT.