He turns midair with his forearms forming an X just in time to block the first sword, allowing it to launch him back and away from the second sword. He lands in a crouch but immediately presses the offense again, aiming for speed and agility to compensate for Tae-gun's weapons and ice-enhanced mobility.

The game is on.

Tae-gun is more mobile—he can fly, if nothing else, and the only upper limit to how fast his ice can go is given by his backlash accumulation rate—and his blades are more dangerous, especially given that he does have prior experience with them. Si-yeon is nimbler, more able to turn on a dime and do acrobatic feats, not to mention that he can easily leap as high as the gym ceiling which mitigates a lot of Tae-gun's advantage through flight. Si-yeon is also reckless, aggressively going after Tae-gun almost heedless of his own safety. Tae-gun, of course, can't let Si-yeon's recklessness prevent him from actually using his blades in ways that would be really dangerous to anyone else as that would be a weakness Si-yeon would absolutely exploit, but Si-yeon can always dodge when he needs to, or straightforwardly tank a hit when that's necessary, though he does that sparingly as it's pretty costly in backlash compared to other things he could do—such as stopping the blades with his bare hands.

It's loads of fun. Fighting monsters is just not the same as fighting another human, and Tae-gun keeps him constantly on his toes. S-rankers are on another level, even if Si-yeon himself is A-rank—although maybe he shouldn't be thinking about "S-rankers" so much as "Lee Tae-gun".

Si-yeon's goal, of course, is to disarm him. In a real fight against monsters there's no such thing, Tae-gun can just conjure weapons at will, but the point of sparring like this is for both of them to practise various individual skills that they can use to build up their arsenals. If both of them were going all-in and trying to kill each other Si-yeon would still be a challenge to Tae-gun but he'd just lose.

But in this constrained situation Si-yeon wins. There are very few espers who can beat him one-on-one in a mostly-physical fight, and it'd have been even more one-sided if Tae-gun hadn't been allowed to use his various mobility aids. In real life he'd have made sure to go ranged and use his conjuration powers a lot more, too.

Not to mention that Tae-gun feels a flash of—something—when Si-yeon disarms him, and he doesn't know exactly what it is, but it's unexpected and it throws him off-balance enough that it takes a lot less time between losing the first sword and the second than it otherwise would. He doesn't immediately give up on being completely disarmed but from there it doesn't take very long for Si-yeon to stop himself from landing what would've been a decisive blow.

Seungjoo claps.

And Yoo-min wolf whistles and says, "That was so hot."

Si-yeon straightens up from where he's crouched on top of Tae-gun and offers him a hand up. "Do I get a prize for winning?"

Tae-gun accepts the hand, dusts himself, and looks at Si-yeon for a second...

...then summons a very thin layer of very cold frost directly over the skin of his face.

"Ack!" He starts rubbing his face to get rid of the frost. "Warn a hyung before you do that!"

He ignores Si-yeon's complaints and goes to pick his swords up. Despite Jaeha's warning that they could handle quite a lot of roughness he still inspects them for damage, and thankfully there isn't any.

"I can give you a prize if you want, Si-yeon."

"Can you, hyung?"

"I mean—"

Si-yeon—looks conflicted for a moment, which is really not a look that fits his face—

—then shakes his head and skips over to the couple. He kneels before Seungjoo and makes a pouty face. "Please, Seungjoo-sunbae?"

"Hmmm..."

He hates interrupting an 18-year-old publicly domming someone but, "Did you want to try the swords out, hyung?"

...oh he did say he wanted that, didn't he? But on the other hand whenever he gets with these two he has so much fun—but back on the first hand he's not compatible with either of these two and he won't get much guiding from them—

"If you look impressive with the swords I'll let hyung reward you."

He jumps to his feet and gets the swords off Tae-gun then starts practising with them.

Sigh. "We should probably get Kim Chun-hee here for his backlash."

"I'll let her know."

Trying this out with zero prior training is pretty costly in backlash but having watched what Tae-gun was doing earlier does count a bit, and he's gotten really good at using the initial feedback of his first attempts to inform further attempts. First he wants to know the proper way to hold them and how to balance himself, then try a first stab at footwork, then some basic motions, then...

It's always interesting to watch Ha Si-yeon learn a new skill. He does some small things really well, then tries them again and does them wrong. Then he tries more ambitious things and does them perfectly, then he does them again really badly. It's a bizarre stuttering process but it actually is informative even when Tae-gun already has the relevant skills.

It would be far, far too costly in backlash for him to try to use his power to actually completely learn how to do it but he can get enough from his first attempts to then just practise specific aspects of the skill without using his power.