Antimagia

Antimagia (アンティマギア) is a manga written and illustrated by Aiya Kyu. The series started in 2011, and is serialized in Comic Gene.

Plot
In a world where magic or demons isn't meant exist, what will happen when the forgotten prince returns to take his place on the throne by using magic?!!?

Prince Lucas, after many years of absence, returns home to save his country from Duke Demonas, a merciless man who killed his parents and stole the throne. And what's this... he does it by using a strange power!?