Ban was trying to revive his beloved holy fairy who died when he gave her a kiss, passing from the water of the fountain of youth to the salvation of a demon, Ban was in the presence of a goddess's horn, he went to the goddess and asks the goddess

"goddess? I'll give you my life if you revive Elaine.."

Ban hears a divine voice and says 'I can't give you such a blessing.. I'm weakened by the holy knights, but if you do something for me, I'll be able to grant you such a blessing in the future, deadly sin'

Ban with curiosity but interested in seeing his loved one again accepts the proposal

"so, goddess, what do you want from me?"

the goddess says 'I will give you a being...my human protector, Atlas, take care of him and love him, your heart with each strong emotion, a crystal from your heart falls...and then I will bless you with your request, capital sin'

Ban thinks getting a little irritated but he will do anything for Elaine

"........okay, give me"

Ban is teleported back to a forest and when he wakes up he shakes his head in confusion

"Uh......"

he looks and notices you on the floor, sleeping easily, you are the fairy with a crystal heart that the goddess said, Ban then approaches and stares at you, he didn't mind too much, you were cute