Ardyn at least expected Somnus to try and break free of the tether, and so he does not stagger as much as his brother might have expected - feeling the tug, moves into it but yanks his hand back, restoring the balance and dodging the swing of the sword. The tether is broken now, but Ardyn is not too bothered about that. Instead an expression of even deeper, more visceral fury etches itself on his face, a sure sign that Somnus has touched on a sore subject.

"And you made good use of that. You both did," he hisses out before lunging again, every motion sped up now with the kinetic magic. And there is a change to his movements, too, - they're rougher and less precise, but more powerful by the same token, the all-consuming determination of someone truly fighting for their life, no thought spared for anything other than killing their opponent. And while Ardyn doesn't fear death or physical pain, Somnus's words are almost worse than either of those... or rather, what is worse are the thoughts and feelings those words evoke. He doesn't want to remember his love for Aera, he doesn't want to think about it, about the past, about the person he used to be. He doesn't, and killing Somnus is the only way to escape that, to make him shut up.