In short, I liked it. A lot.
A couple of things:
I'm not sure what has happened before this, of course. This is the first chapter of yours that I've read. Does the main character come from a different planet or something? I just wondered if that was the reason you have him so strongly contrast with everything else that seems so medieval in the setting and dialogue with other characters.
Second, I have to agree with the others. The descriptions during the fight scenes, while helpful, are somewhat jarring. When you get around to editing it, I'd suggest taking each movement separately, and trying to find one sentence, two at most, that really shows us what's happening. That way we still get your expertise on the fighting scenes, but we're not as easily taken out of the scene by too much description.
As to the scene with the Sigil Knight. I enjoyed the battle. The only line I had a problem with was
"it is said that no mortal man or army has ever defeated one.”
I think that clues us in a little too quickly to the knight's demise. We know that they're going to defeat this thing in the exact same sentence that we learn it even exists. Maybe increasing Kajsa's fear of the Knight would be more effective than this line at all, especially after Kail has just seen her ripping heads off. Maybe he can think about how bad this Knight must be if someone that just destroyed an entire room of dudes is shivering scared. Also, after the battle, I think they should both just barely escape with their lives like Falcon said. I DO really like the idea of the blonde shooting her with the arrow though. Nice work!
In short, I'm a big fan of this, and want more. Gimme, Gimme!!