Cairbre

Often seen in the company of Morgan & Malcolm. Cairbre is a large man, roughly seven feet tall and proportionally broad-shouldered.
The three often hire together as caravan guards, security, or day laborers. Cairbre carries a greatsword which, proportioned for him, is great indeed. This is a marked distinction from Morgan and Malcolm's rapiers. Cairbre is competent enough with his sword, but Morgan and Malcolm work hard to keep him out of fights or situations where he'll need to defend himself.
Cairbre appears to be a little older than the twin brothers, about thirty. He is friendly and good-natured, often ready with a joke, and he frequently reins in Morgan's teasing or Malcolm's sulking.
It is curious to note how seemingly protective Morgan and Malcolm can be of Cairbre, given that he's so large and clearly capable of taking care of himself. A careful observer will note that they nearly always flank him, Morgan on the right and Malcolm on the left. (This is, incidentally, one of the simpler ways of distinguishing the twins.) Given Cairbre's obvious status as a person less likely to be targeting for casual robbery, this may be a misunderstanding of some other dynamic in the friendship.
Normally non-combat magic can be used around people without ill effect, but for Cairbre, it's different. When touched by even innocuous magic...

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Cairbre gets real ugly when hit by magic. Like, real ugly. Big tusks, contorted, porcine features, and very short-tempered. Not at all the jovial big guy we generally know and love.