It's because..
Rhys wanted to discuss with Kazuya regarding the warning Shioka gave him regarding Lyn's fiance. However, when he found the man, Kazuya was covered in wounds. His gaze dim, Rhys placed his hand on his shoulder, and Kazuya immediately drew his sword on him.
"Kazuya, it's just me."
Rhys is calm, however.
"Rhys," Kazuya mumbled. "Lyn?"
Even in this state, Kazuya is still thinking about her. Isn't that normal? Isn't that a good thing? Usually, when Kazuya gets like this, he doesn't think about anybody else but himself. No, all that is on his mind is fighting. Such a hazard and dark gaze. Rhys bit his lip; he knew he ought to have gone instead. What kind of things has Prince Allen made Kazuya do? He knew the two temporarily teamed up to get to the bottom of whoever hurt Lyn. But Rhys didn't think he would find his friend in this state.