Kylo's reflexes are certainly sharp enough to allow him a liquid shift out of the range of Ronan's blow— and only just. No wasted energy here. The tight motion carries and returns through his body, perfectly balanced, attention still focused on Ronan's face. It seems they're both testing eachother.

Not being a boxer, Kylo's stance is more firmly grounded than Ronan's. He looks more ready to brawl and grapple than deliver sharply aimed jabs, and he doesn't seem overly concerned with defending himself at all. His, he suggests with his fully squared approach, is a body that will outlast attack.

The deeper inhale is the only warning given before Kylo surges forward, committing to a hefty swing with an almost ridiculous amount of power behind it.

It's entirely possible he's aiming to impress.