"This place clearly doesn't fear us, if anyone was this bold." Jesper doesn't necessarily want that to change because that could go the wrong way. They could end up on jail or under closer watch, the freedom they have in Free Cities is unique. Thorne's locked up tight. He doesn't want that. But it also stands to reason that these nobodies, these cultists, snatched Summoned right under his nose, powerful ones, and fucked them up.

"I think between the blood we spilled and destroying their cavern, we may have made a good point, but imprisonment sends the wrong message." Jesper killed several acolytes himself. He knows that the cavern essentially fell on itself before that turtle (??? still strange) saved them. The point is that the Summoned slammed into the kidnappers and punished them, it was a good warning. They didn't need the factions to do it, they made a strong enough statement.

But mercy doesn't give people good reasons to listen. He's grumpy about it, that's all. None of his people voted for mercy. There's no such thing as it in the heart of the Crows when it comes to vengeance.

"I won't forget. If I have to swing back around in a year I will." He can hold grudges for a long time.