He decides to try!

"...so, you think Rhea is aware that a potential Goddess is in my head?" Byleth asked Sothis slowly, who shrugged as she floated before him in his room.

"It's really not out of the question, Master," she told him. "Given all that we have put together thus far, it's not far fetched."

"...so what exactly do you suggest I do with this information?" he asked. "Go right to Rhea, tell her about you, and say we both agree that if Lonato can be talked down, the matter of his planned rebellion should be dropped?"

"...I can't even tell if you're being sarcastic, your tone didn't change enough for me to figure it out," Sothis sighed. "But yeah, we could definitely just straight up go to her and see how she responds. Worst case scenario, if things go South, we just reverse time, and she won't know a thing!"

"...you do realize that she detected you already, right?" Byleth inquired. "Who's to say that she won't be able to tell if we turn back time?"

"...okay, good point," Sothis conceded. "A wish could also fix it though, you just gotta get creative as always. Let's just... See what happens."

Byleth slowly nodded, getting up, and began to walk towards the Archbishop's chambers. He knocked and Rhea called for him to enter. "Archbishop," he greeted, noting Seteth in the room with her. "May I speak with you in private?"

"In private? Out of the question!" Seteth sputtered, looking rather offended at the very notion. "You're still someone we can't trust completely!"

"Seteth, enough," Rhea replied as Byleth took his sheathed sword off of his belt, and handed it over to Seteth.

"If you are concerned, I'm now unarmed," Byleth told him. Seteth narrowed his eyes, still not trusting Byleth's intentions.

"Seteth... Leave us," Rhea nodded. Seteth began to protest, but Rhea silenced him with a raised hand. "You know I can take care of myself. And despite your misgivings, I do trust the Professor for a reason." Seteth looked like he wanted to argue further, but ultimately gave up, and walked out. Though Byleth had little doubt he was going to assemble some Knights to storm in at the slightest sign of trouble. "Now, Professor... Byleth, what brings you here to me now?" Rhea asked him.

Byleth took a deep breath. In for a gold coin, in for the full bullion. "Archbishop... Did you somehow put the Goddess inside my head?" he asked her, getting straight to it.