Somehow, it doesn't surprise Prompto the Chantry would disavow such things, even if they were real. But then there's much about the Chantry that Prompto doesn't agree with or understand. However, Saoirse is devout, as is Myr, so he's long since learned to keep quiet about it. He respects their faith and beliefs, and given that he's a Rifter, he has little room to shit on the Chantry. As much as he kind of wants to sometimes...

The use of the past tense isn't lost on him, but he lets it go. Ten to one Myr will explain that later on.

"Those sorts of things tend to happen in the weirdest places. Remote islands seem like prime miracle spots. That and creepy underground tombs." Don't ask. "So you knew about it but didn't think much of it. Okay. What made you change your mind?"