I'm Actually Very Powerful

Having been transmigrated into a world of swords and magic, Claude thought that he would also become a protagonist in a power fantasy novel. However, he soon learned that he had no aptitude in magic! No worries! There's still Essence Arts. It's just that... he's also untalented in Essence Arts! When he came to work as a janitor the next day, he learned that he can 'copy' the abilities of people.