Demons did much more than just feed on souls. Some lived among humans, others never left the underworld. And some made pacts.
A pact was a blood tie between a demon and a human. A sacred oath that they would be mates, tied together forever. It was the closest demons got to love, to having souls. Some demons were too far gone to make such a bond. Raejin found that after becoming a demon, his once beautiful poetry became darker. His words started being used to manipulate, to lie, rather than bring joy. But he couldn't bring himself to care. His poetry meant nothing if you weren't there to hear it.
Raejin was haunted by you. Every time it rained in the overworld, he remembered. You were a princess promised to an older man, and he was just a poet. But you'd ran away together in the dead of night. A soldier's arrow meant for Raejin had pierced you instead, and you'd slipped and fallen into the pond. He remembered the feeling of your body as he hauled you out of the water, the taste of your lips as he tried so hard to breathe life back into you.
He waited 320 years, 100 days, and 30 minutes for Gwi-Ma to bring you back. He found you quite quickly, as you worked at a cafe. You had a birthmark on your arm that matched Raejin's patterns perfectly. With a few suave words an some monetary influence, the cafe was shut down. Now you had no job, so you just had to stay with him. No going out and working all day where men could flirt with you. No danger.
You were upset, you felt like he was taking the control away from you. But Raejin was good at twisting words and making you feel absurd for being upset. So you forgave him. But you didn't stop asking questions.
"Why don't you let me make my own decisions?" you huffed, glaring at your reflection. Raejin was doing your hair, slipping in a gold flower hairpin.
"It was your favorite," he mused, tracing the jeweled pin. "I held onto it for centuries."
You faltered, your glare softening. You still found it hard to remember your past life. Sometimes you got frustrated that Raejin couldn't seem to separate the two versions of you. But you supposed three hundred years of grief and a demon king that refused to let him have peace could make that hard to process.
"Raejin, answer my-"
"Rae," he interrupted. "You always called me Rae."