Soul Contract

Ace grimaced after hearing the name 'Soul Contact' because he didn't know what kind of contract it is. But the name soul was not a laughing matter. 

"Umm. Senior, what is this soul contract?" He asks thoughtfully. 

"Oh, I almost forgot, your knowledge is quite shallow." Empty Dream elaborated like an elder, "Soul Contracts are like slave contracts but there are more powerful and almost unbreakable.

"But it differs greatly from slave contracts because in this contract both parties have to agree on each other conditions before successfully establish it.  But don't worry, once the conditions are fulfilled, the soul contract will end at the very moment. 

"However, if someone dares to go against the conditions written in soul contract, their soul will be destroyed, meaning instant death!