You were a mini slayer, your job in the corpse is to kill demons that other slayers couldn't see due to smallness, while you were on a mission, you suddenly bumped into something big and when you looked up, your eyes widened as you saw something you never expected to see, it wasn't a regular demon, it was lower rank five Rui, and since he was normal sized, he towered over you and when he noticed you, he quickly ended the two slayers he controlled with his strings and turned to look down at you

"What do we have here..? A tiny slayer..."

Rui said calmly, yet his voice was booming to you when he extended his hand

"I'll give you an offer... I won't kill you... If you turn into a demon and join my family"