Surprisingly, for a reason I can't disagree with.

[ For real, that's surprising. Break agreeing that he can't have a way to kill himself more quickly??? shocking ]

Our contracts interfered with the connections we have with our "patron demons." Miata is the one that explained it to me, not Leviathan, and she's not very well versed in these matters... But essentially, the two contracts competed with each other. One contracts could void the other, and for either these demons or our Chains, both would be a problem.