You're doing it wrong...

I thought putting a building would open the way to Atziri, but...



After several run almost all other rooms were wiped excepted the one I want to, what do I miss?

It must be a path tile. With the recent changes to reducing room wipes you're just going to have to keep trying until those two rooms are gone. Keep hitting architect tile to speed it up.

im so over this mechanic, ready to wait til next league. i have run a bunch of temples and have yet to be able to fight atziri. i get path tiles but when i try to use them there are no squares lit up, half the time i open the temple i can only place 1 of the 6 tiles even though my temple is only about 20% full. its a shit mechanic.

Did the same as you and my temple is bricked on my main character.

I just ignore it and when I have 12 crystals I pop in, use console, close temple to let it self delete stuff and go on about my life.

One day maybe the game will decide to delete that single room that leads to Atziri and is not connected, but I doubt it.