Universal Contract

In the Dark World, they're 2 precious artifacts left b the Shodaime Onikage, Ryu's Onyx which holds the soul of Ryu, the shapeshifting demon that is said to twist the heavens, burn the wind, and powers beyond the world, the second was the Universal Contract, which allows the summoner to summon any creature they wish. But there are some drawbacks and requirements:

1:The only ones who sign the contract can only be blood related to the Onikage

2:If the signer covets another's summon,then the signer must kill that person and use their blood to gain control over that summon. Then the signer has access to that summon(Species)

More soon!