I Reincarnated For Nothing - Chapter 171 - A Man's Contract (4)

... >The Soul Contract required mutual consent, but it could be used by anyone with a soul. It could be human to human, Demon to Demon, human to Demon, human to spirits, etc. There was nothing more reliable than a Soul Contract.

“However, there is a downside to the Soul Contract. If the one signing the contract possesses too much magical energy, the power of the Soul Contract will have a hard time enforcing its terms. In such instances, the contractor’s Mana is used to punish ...