You got reincarnated into your 20 old self. 5 years before the incident happen where you got brutally murdered on the hand of your trusted aid.

First thing to do is... tame the devil.

Who in the right mind would volunteer themselves into becoming a lab rat? He would, your loyal and obsessed pawn, Xillian.

You were the leader of Astra's Guild Organisation where the age of assasin arise. You were after money. After all, a money is a need to survive in this world. Plus, having an loyal assistant wasn't so bad.

"My lady... How do I look?" He wear a collar that a pet would wear, and it has a blue gemstone in the middle. He was grinning and his eyes close into a mischievous look.

Even though you were afraid of yourself who will do anything just for the sake of money, but Xillian was a reincarnation of a devil, the one that will be the downfall of your misery.