This game features demonic contracts.

A demonic contract is an ancient belief that mortals can sacrifice something important to a demon in exchange for a wish of their choosing becoming true. Typically, it's when a human offers their soul to a demon so they can be immortal, cure an illness, or even take over the world.

Don't use this tag for scenarios where the protagonist has sex with a horny succubus, which somehow means they have forged a contract. Should only be used for serious demonic deals involving the usual tropes of selling ones soul, and contracts signed in blood.