I know I'm being nitpicky... but he had 1012/1012 MP before opening the "item box." Then, after two fire type spells (one being a flame in his hand, while the other was an actual attack), he leveled up and had 508/1512 MP.
He used 504 MP, almost half his MP, for those three actions...?!?
I'd understand if he used 50, that being way more than what an "average" person of that world has (10)... but dang, 500 seems a bit much.