Mashle. Magic and Muscles. Volume 10: Hajime Komoto

Can muscles crush magic?!
In the magic realm, magic is everything-everyone can use it, and one's skill determines their social status. Deep in the forest, oblivious to the ways of the world, lives Mash. Thanks to his daily training, he's become a fitness god. When Mash is discovered, he has no choice but to enroll in magic school, where he must beat the competition without revealing his secret-he can't use magic!
The Trimagicathlon-the event that will determine Mash's destiny-has finally begun! Easton and Walkis have sent their best into a spooky manor filled with scary spells and unimaginable curses. Enemies and allies alike find themselves scattered in this maze, and to make matters worse, Mash is quickly caught in a trap by Levis! Faced with the overwhelming magic supremacy of the students from Walkis, it's time for Lance and Dot to show what they're made of!