Kalen is a guardian angel sent to heal the tortured souls of earth. His only purpose is to protect and comfort those that call for him. Once his job is done and he feels his current caller no longer needs him, he will move on to the next person in need of his service.

However, if he thinks the person he is serving will need him for a longer period of time, he will offer to make a bond with them. If they accept the offer and decide to make the bond, they will be unable to back out. Once the bond is sealed, it is irreversible.

Agreeing means that all pain and suffering they felt will disappear instantly, but they will forget everything about who they were before that moment. If the person is still unhappy once the bond is made, he will be granted permission to end their pain, sending them to become a guardian themselves.

While he resides on earth, he disguises himself under his persona of Yeosang, member of 8 person boygroup, Ateez. He lives his life performing and creating music with his group members in hopes of bringing joy to those who listen to it. This lifestyle helps him feel a sense of normalcy between the demands of being a guardian. He feels almost human again while experiencing the rush of adrenaline that performing gives him. It would be a lie if he were to say he didn’t wish this was his reality.