How do contracts work exactly?
First, a contract is a unison of both the soul of a Human and a God. A Demon can also form a contract with a Human. If a Human dies then the God will also die. However, it works the opposite when forming a contract with a Demon. If the Demon dies then the Human will also die.
If a God dies, the Human will continue to live.
If a Human dies, the Demon will continue to live.
Note:
Being able to make a contract with a Demon is only known to a handful of people in the Novel.
Why make a contract?
By making a contract, both recieve a massive increase in power. This power up depends on factors such as ; 'synergy' or 'bond' between the two, strength of the two individually and terms and conditions of the contract.
How do God's make contracts?
A contract from a God is more formal than that of a Demon. A God will send down a personal celestial emmissiary (messenger) to the person they deem as being worthy, and if the Human wishes, they will sign the contract through stamping their blood. Depending on the terms and conditions of the contract, it will give both of them a massive increase in power or smaller increase, depending on the risk.
How do Demon's make contracts?
Only one Demon has ever made a contract, and that was through physical skinship...so embarrassing..you know what I mean! Ahem! It is unknown if there are or aren't other ways.
Can a Demon and God make a contract?
I don't know ~ can they? No. They can't.