"Decided he didn't want to put up with O'Connor for the night, so he's sleeping outside. And we're talking priorities for when we get to town, got anything to add? Need to settle a plan before I go under, here." Fionn decided that he should probably address the ticking, bruised, concussed timebomb before diving, too.
Turning to O'Connor, he started speaking quietly enough that the others, still scattered around the cabin or area outside, wouldn't hear it; what he needed to say didn't need to be public. "And I don't much know what you're thinking, mate, but you really ought to consider something: we're not getting home unless we can count on each other. I don't know if you've had anyone you've been able to trust or not before, but at least with this bunch you've got the reassurance that we all need each other. And if you don't believe that, well, consider that most of what we do next is on my shoulders - which means, like it or not, you're having to depend on someone else same as you expected us to depend on you to do the shooting if we ran into any trouble on the way here." He paused for a second to choose his next words with a bit of care. "Seems to me you've got two choices: calm your ass down and stop acting like you could explode on the rest of us at any second, or you can push us all away and find your own damn way home - we're all in this shit together, but that doesn't focking well mean we have to put up with that bullshit. And while I may not be much of an expert, seems to me the latter is the way of a thick bloody moron with something to prove, and not that of the badass you make yourself out to be. A real badass isn't driven to constantly demonstrate it to everyone around him, and he sure as hell doesn't drive away people who could help him for no good reason, regardless of whether or not he needs them."
Might be I can't keep his ego from driving him, but I can sure as hell try to orient it in a more useful direction.