While Aang has been dead and reincarnated, he still shows up in the new show. Apparently his body gave out too soon mainly due to his century long slumber before the start of Avatar: The Last Airbender.

He founded Republic City with his friends and we see a bit of that in a flashback. Mainly about a crime lord named Yakone.

Yakone turned out to be the most powerful bloodbender and almost gets the upper hand on Aang. But Aang manages to use the Avatar state to win and take away his bending abilities.

While his soul is now Avatar Korra, his spirit and memory still exists independently. He helps Korra when he can like Roku did for him. I forget exactly why, but Korra loses this connection to him and all previous Avatars, which bites.

I did enjoy seeing Tenzin being able to see his father’s spirit and make peace with him.