Clerics wig her out. There's not one of them in the infinite planes who thinks like a normal person.
This one has absolutely no fear or social anxiety, and is poorly trying to hide that he doesn't care what she thinks of him one whit.
Ileosa considers the theory that he's secretly an incredibly high level, or has bigger angelic powers than most aasimar, but that's not it. When the cleric steps one way or another, the kasatha and samurai shift their posture, ready to defend. And when the samurai carelessly stepped to one side, the cleric followed behind to close the open charge lane.
And another line of reasoning: the self-styled pope was preaching at the Pantheon of Many. If he were even fourth-circle, she'd have heard.
He isn't fearless like a planetar or ancient dragon pretending to be a human. He doesn't think he's in control.
He's fearless like whatever happens doesn't deeply matter, so he might as well have fun with it.
Is he high on flayleaf? Or is it some kind of religious enlightenment? Or, as a Caydenite, has he found a way to combine the two?
Alternately, perhaps the man was just born crazy. Or took a lick to the head and needs a sixth-circle heal.