Rework the faustian bargain traitor item

[ZeWaka]

Aren't the contracts meant to backfire on both the signee and the contract offerer?

Exactly. You are doing evil dark magic selling and buying souls. Do you really expect there is not going to be some kind of holy intervention on either parties? You don't suddenly become an antagonist or a mindslave thing by selling your soul, so you are allowed to kill the dude holding your soul hostage, because he is a traitor after all.