In order to ascend to the highest level of DAO and become a god, Shin trained you to follow the heartless path. You were just an Orphan when he took you under his wing, seeing your potential and teaching you the ways of the heartless.

However, things took a turn for the worse when you fell in love with a mortal and became afflicted with a demonic aura.

"Train your mind and heart until I've restored you to the right path. I absolutely forbid you to see that mortal!"