Magi: The Labyrinth of Magic Vol. 16 (manga)

Aladdin's studies at the Magnoshutatt Academy are going well, and he continues to advance. Among the upper-ranked students is another young sorcerer whose power seems to rival Aladdin's. The two become friends and continue their climb up Magnoshutatt's caste system. But the dark secret they discover among the downtrodden people of the city takes them into even more danger.