Demonic Soul Transfer Technique

Demonic Soul Transfer Technique allows the user to, essentially, merge with whichever demon they signed the contract with. The user gains the demons power and appearance in exchange for a piece of their life-force each time it's used. Labeled a Kinjutsu by its creator Katsuo Senju because of its drawbacks, he has stated that only those born of the Senju or Uzumaki are able to truly use this technique, as their life-force is so strong. Each person can only have one blood contract.

To summon a demon to bind in a contract, the user must sign their name in blood, on a special scroll created and hidden by Katsuo Senju, the scroll reacts to the blood placed on it, summoning a demon, what demon is summoned seems to be based on the users blood. Once summoned the demon will converse with the user to create their contract.

The only person alive with the knowledge of where the scroll is as well as the mechanics behind using it is Kazuma Senju after his grandfather passed its secrets to him.

The technique seems to have two different forms:
 * Half-Transformation(半化), "Hanka": This form takes on only half the demons appearance merging its features with the users features. The power granted through this form is much smaller, but does not tax the users body as much as the complete form.


 * Complete-Transformation(完成化),"Kanseika": This form takes on the full appearance of the demon, granting the full amount of the demon's power, as well as physical features. While not only taking a piece of the users life force, this form also seems to cause a large amount of fatigue in the user.