So Baku could have been at a 1/6 going into the game, but instead he's at 1/7 still. That said, I think he discovered something while facing off against Suteguma, maybe when he tackled the guy down the stairs.
The chief of the Funeral Division being the one to enter is interesting, since it seems like it ties into what Tatsuki said earlier about Yakou "Even living until then".
I'm not sure I agree with Leo and Ranko about Baku being unaware of them, as well as the reason he left the first floor. It wouldn't be the first time a double camouflage tactic was used.