The first thing he notices is how different the magic in the air feels. By the time he turns around towards the entrance, he already knows it’ll be gone. The white walls have sealed behind him like they were never open to begin with. That doesn’t stop him from trying to break out though. He punches the walls on their stupidly smooth surfaces, kicks them, wishes for a moment that he could torch them or shake the ground to break them apart. Although maybe his kind of magic doesn’t work here because whatever force brought him here doesn’t follow it. Magic doesn’t work that way, it can’t just kidnap people!
After a few more hits -that only succeed in making his hand hurt- Kellen decides to give magic a try anyway. His magic isn’t particularly strong and he might need it soon for something less… outside of his capabilities, but he’d just been walking home until a few minutes ago and now he’s in a weird corridor so he feels like it’s justified if he isn’t thinking straight. Shaking away the extra doubts, he takes a deep breath, trying to calm down his racing heart while also using it to connect to his magic. At least that’s an advantage of being air-inclined, one’s usually surrounded by their element. It would be pretty hard for him to connect with fire or earth in this strange place where the light doesn’t seem to come from a sun and the floor is just as artificial as the walls.
Once he can feel his magic itching under his skin, ready to burst out, he crouches down. With a small nod to himself, he exhales and jumps. He lets out his magic, a strong gust of wind pushing him further up. Still, the walls around him are absurdly tall and he can't even glimpse over them before falling back down. Luckily, he does have enough power left to slow himself down and soften the landing, although it drains his reserves. He doesn't know if the atmospheric magic here will work for him to recharge with but it's not like he can go back in time to change his actions anyway.
So, with his thoughts still racing, trying to find a way out and back home, he sits down on the floor. He rests his back against the wall and closes his eyes. Magic exhaustion feels, well, exhausting. It's not particularly surprising then that he manages to doze off despite his unease.