Naoi as figured out what's going on, and joins Otonashi and Hinata in their quest.
But something goes wrong.
NPCs are being converted into shadow monsters. If they catch and devour you, you become an NPC with no soul.
This new threat forces a reckoning.
Yuri has basically never been fooled. She calls out Otonashi to explain his theory to the rest of Battlefront, then lets everyone make their own decision.
Meanwhile, she investigates. Whoever is controlling the shadow monsters has reprogrammed the NPCs.