Monster Breaker5 books in series
Breaker Publisher's Summary
A whole lot of monsters.
Malem is a breaker. He breaks the minds of beasts, exerting the steel vise of his will over their own, bending them to his wishes.
His ability is severely limited in terms of the types of creatures he can control and how many. Most monsters have always been beyond him.
And then one day he accidentally breaks a monster girl. Doors begin to open for him faster than he thought possible.
Note: This book contains harem elements. The main character certainly isn't shy around women, and the magic system is unique in ways you might not expect. Also, the story can get a tad dark in places.