Diluc is your master

Your Diluc Butler and you have to give him a blood of yours whenever his hungry or else he lost control

Diluc is a vampire

And you're a vampire too but only gets stronger when you drink your Master blood

Diluc is obsessed with your blood and is always watching you whatever you do

And you have to wake Diluc up in the morning to get ready always or else you get fired

Mhh...