Kjartan

Kjartan is a Dane warrior in Earl Ragnar's household, a man of low birth who has clawed his way to a trusted place at his lord's table without ever being treated as an equal. Sullen, watchful and quick to take offence, he nurses grievances about status and respect that simmer beneath a loyal soldier's surface.

Alexandre Willaume plays Kjartan's resentment as something physical — a coiled stillness that makes his courtesy feel provisional. The show gives him real grounds for grievance before showing what he does with them, so his menace grows out of recognisable humiliation rather than cartoon villainy, and that restraint is what makes him unsettling to watch.