Legend of Korea is a bit all over the place. Season 1 is tough to get through but pro bending is really cool and the evolution of the villains from the one dimensional firelord to Amon is really a great transition. Those that say the time jump is too jarring need only look at the late 1800s to post WW1 era and the technological advancements made during the time.
Season 2 is pretty bad. However there are bright spots like avatar wan’s arc and the character developing journeys a lot of the main and supporting characters go through.
Season 3 is hands down, bar none the best SEASON of AVATAR period and I will fight you. The characters, the villains, the building of the world, it builds on ATLAs success and finally gets back to it.
Season four continues that trend and is good as well.