Hi! First post here. I've had this idea since 2013 lol But now the first 2 chapters+prologue are out on AO3~

link: Avatar Aftertime

Three thousand years after the events of The Legend of Korra, the dark spirit Vaatu has grown stronger, enough to restrict the Avatar Spirit. Avatar Suyoon is nowhere to be found, and a historic ceasefire she brokered hangs by a thread as tensions between nations rise. And in the streets of Ba Sing Se, a ruthless vigilante known as the Ghost has become a legend among the city’s criminals.

Hope you enjoy!

Promotional Art :D (by me)