Cain Knightley

Cain is a young wizard that resides within Central Country. He is a former general and commanding officer of the knights in Central Kingdom. He's outgoing, caring, and friendly, and has no difficulty getting along with anyone. Despite being a wizard, he's more adept with a sword than he is with magic. His left eye was forcefully taken and exchanged with one of his own by Owen, which Cain has claimed he'll take back with his own strength one day.

(Source: Promise of Wizard Wiki)