Kora theory
One thing that was never concluded in Kora was that weird spirit that looked like kora in the avatar state that just stalked her
Iirc, all we were told is that it was a spirit.
what if it was the old lineage? The past avatars were disconnected from Kora (more so Rava), but never from eachother persay
What if them being disconnected from Rava “corrupted” then almost, or more so left them incomplete. I know the “glow” of the avatar state was said to be Rava, which was sorta the explanation of why Kora had a ”avatar state” to begin with after s2. But in ATLA, it was said to be all the past avatar‘s. By that logic, this spirit would basically just be a walking avatar state, and it does share various behaviors with it. Being emotionless, almost zombie like, etc.