That....was a fatal mistake she did. Showing him that she was a fire user. Although he might look like a young adult and exceptionally dull in a glance, the swordsman has a personal distaste against fire users, provided from all his experience as an ice/water user during his countless travels from one place to the next. Recalling most of the accounts of being ass-whooped by people using fire during his travels, the swordsman has spent months and years on developing a combat method to counter the fiery bastards who think too highly of their flaming armor or weapon. Though not fine-tuned and perfected, nonetheless.
And he wasn't certainly going to let her keep that grin on for too long.
Not knowing how strong or how powerful her flames might be, the swordsman wasn't inclined to hold back at the very least. Taking another step forward, pushing nearly his entire weight against the left handle of his blade, the block of ice provided him a good defense if the girl tried to attack him head-on, much of the density still concentrated on the outside and the layers giving him time to react when need be. He watched the girl approach him with steadfast motions, using his vines as stepping stones.
Why that little...!
Well, the vines weren't created just for ensnaring her, after all. Restricting her movements so she won't realize his ulterior motive, if and when Roja notices, it would be that the moving tendrils were intentionally leading her to him - a clear line of view, with the vines cornering her into place indirectly, with subtle motions. It would all be clear, when the swordsman, since the start of this round, finally shouts in thunderous rage, readying the blow that he has been waiting for;
**"KU-RAI-E!" (Take this!)
BOOM!**

A focused beam of highly concentrated ice and water - a density beyond any possible means by mother nature - erupted straight out of the block of ice in front of him, careening towards Roja to impact her entire body at full force due to its splash effect. Made of huge quantities of water and constrained to a size no larger than a baseball from the origin, he was using the pressure of water to his advantage, adding strength and endurance to the point where it can resist fire to a large extent, while packing a force to be reckoned with . Even if evaporated, if the flame is too strong to handle, that poses an even more lethal problem for fire users;
Highly concentrated steam that can incite massive burns to the skin.
Such frightening speed the beam then traveled, that the speed of the vines which was to ensnare and constrain the girl were of no match to the monstrosity of the beam's charged release. Should it hit, and the swordsman highly doubt that she could avoid it at such a distance and at such a short time - as he has painstakingly led her to this strike - the force of the beam was more than enough to stop the girl in midair nearly immediately, and even hurl her straight backwards into the sky, dozens of meters high and out of the arena easily.
To add to the killing blow, the left blade which he'd use to trigger the strike... Would be inside the heart of the beam as well upon release, adding a maiming stab that can, if he had aimed correctly, pierce straight through her left torso and cripple her side without being lethal in the follow-up strike. Should the beam miss its target, of course.
Wishful thinking on his part if all goes well - the beam and the sword hitting her in consecutive strikes quickly, the swordsman, however, didn't want to spare himself the luxury of thinking that this is the finishing blow to this round. He still kept his right blade in check, the block of ice around him acting as a shielding if things....didn't go well.
In which he sincerely hoped that he is wrong about his delusional caution. He'll just have to see how Roja reacts, and add a few minor manipulations so that all that charged energy won't go to waste if it misses. Somehow.