Contract締結 is so good :(Recommend me some

Who gets it? Ciel made a contract with the demon Sebastian, offering his soul as payment. The demon helps him get revenge, and once it's done, he takes Ciel's soul. The dynamic between hunter and prey is just *chef's kiss*! Ciel: Demon, help me get revenge. My soul is the price. You must protect me and never betray me. Sebastian: As you command, Yes, my lord. I am merely a butler. Ciel: You're staying by my side only because you want my soul, right? Sebastian: Yes, I look forward to tasting your soul.