The Tale of Matthew Frederick

A boy who is born with a hidden secret grows up to be just an average teenage boy. Until one day, an angel named "Etlas" appears to him at his job and it says "I've finally found you, Matthew Frederick!"
Together, they embark on killing demons and monsters who take the very souls of humans. Can the sword Matthew Frederick was born with help him become a full fledged 'Angelic Warrior'?