"Not a big deal? There are actual tendrils growing out of you hand! I'd say it is the very definition of unhealthy!"

Kell doesn't have a lot of patience in normal circumstances. Those here, are very much not. So he has even less. It only makes matters worse when he sees Wilhelm use magic to make the meager flames of their campfire - the one he spent so much time and effort building - licking the dead rat bigger. Magic! He knows it's magic, he can feel it. To see Wilhelm use it so effortlessly when his own remains mostly blocked, unstable, out of his reach. The view transforms Kell's growing irritation into pure envy. He knows it's Acolytes doing. It's a calculated move to drive a wedge between them. He knows, and can do nothing to stop reacting to it the way he does.

Then Wilhelm hits him when it's guaranteed to hurt the most.

"You leave Rhy out of this!" Kell snarls, both his hands tightening into fists. "What did you tell him, Wilhelm!?"