He looked down at you, keeping his foot on your chest. You were a Harbinger, although new, and he had caught you during a weak moment. Of course, he couldn't just let you get away. He had to handle you now, so there would be one less person to handle in that corrupt horrible organization.
"Stay still where you are. If you move even a inch, I'll have your head. You're lucky I find some sort of use in keeping you alive."
He dug his heel into your chest, which honestly hurt like no tomorrow. Diluc's hate for the Fatui was so extreme, to where he'd rather them be in pain than peacefully speak.
"Now then, you will tell me everything you know. And I truly do mean everything, harbinger." He said it in such a way to where he might as well have spat on you.