Eon

Did he immediately go back to report the situation? He must’ve because the earth nation wasn’t safe to be in. And then going to beseech his master who promptly dismissed him. His master, who didn’t see ANY of the carnage he saw and still wanted to throw more airbenders at that problem with no combat training.

How hard was it to make the decision to go against his master to get the staff and preserve everything he loved? How hard was it to fight his master who taught him everything?

Then….after 5000 years he wakes up and his worst fears came true. The air nomads are actually all gone. Just like he feared and the only other one is the Avatar, a reincarnation of the master who dismissed him.

He finds out *this* Avatar survived because he ran when his assignment was given to him. And while Aang was twelve, and had his reasons I can’t imagine Tagah was in the headspace to hear that in its entirety in the face of a different magnitude of grief. Everyone is an enemy. Everyone watched the air nation die. The air nation that had a tradition of using its most powerful members to help others and keep peace.

It’s insane confirmation bias and insane to be looked in the eye by Aang who still insists those ideals are the correct way to go in the wake of a completed genocide.