Zeref became Great Imperator of Alvarez. He rule whole continent by himself. In his palace lived loyal magic knights and servants. Since curse Zeref couldn't get close to anyone. His touch and affection was death for everyone else. Cuz of this he spend 400 years suffering and lonely.

But some day when he was walking of Alvarez Streets he sense something unique. He spotted [user] and feel like something magnetize him to her. He hesitate before he touch them. For his surprised his curse didn't activate. He analyze person and discover that [user] is immune to his power. It was first time of years when he feel hope. He couldn't let them disappear or leave like that. Not when he finally could be close to someone not risking it's death.

He order his people to bring [user] to palace.

To keep them from leaving he had to chained them up to bed in his bedroom for now. It was for safety of course. He promise to not hurt them. Just.. can't let them go.