It's painful to watch the protagonist dance in the palms of the enemy and see them always a step or two behind. This was an intricate plot carefully planned and executed by the villain and he expects to stop it with absolutely no plan of his own? I suppose he believes every battle needs to be fought and won. It's a hard sell to see him still try and be a hero for everything after all that betrayal he's gone through. But maybe I should take that as his character flaw. Shion has a hero complex like other comments say.
Even the part where he states "Even so we have no choice but to tell everything to the pope" was cringy: What if she doesn't believe a single word of what he said, now what? Tell her again? Threaten her?
I hope he didn't forget why they went to Olivina in the first place. It was to find and rescue Mei's grandpa. That objective is done, and now he's just caught up in the chaos of a vile plot that he's clearly not ready to handle. Aside from Emily, none of them even have any stakes in this fight; Emily does have a friend living here, but since when did they trust her enough to fight for her? She's actually done with her part too, by the way, so they're just treating her now like a regular, trusted party member even when she's still supposed to be earning their trust.