Chapitre 42: LEON X EMILIA R18(1)

A soul contract is a contract between two people. No one knows the actual source of the contract, how it appeared, and how it even works 

But what is known is that if either party violates the contract, he dies 

Yes, this way I can be sure that you will not turn against me, and you will also be sure that I will not turn against you

After a short while, Leon took out a piece of paper and a book containing the contents of the contract, cut his finger, and put some mana in his blood. Emilia did the same thing, only that Leon was the one who saturated her blood with mana, and it fell to the two of them with their blood.

Once they did that, the contract disappeared from their sight, even if it was strange, they ignored it in favor of something more interesting.

Leon looked at Emilia and said, "From now on, you are mine, and my subordinate, and my right hand. I hope you will not let me down."