Also known as Ogre’s Death in Five Years the Kaishuken is a lethal technique that if perfectly executed will inevitably cause death in 5 years. During these 5 years suffering comparable to having your insides eaten by a demon will come and go. It’s not simply violent pain. But the most extreme suffering a human can feel. A huge amount of foreign ki is infused into the victims body trapping it within their own poisoning their aura. Since the energies aren’t compatible it disrupts the natural flow of victims ki preventing them from healing. Since its not their ki they have no control over it so they can’t just expunge it. And it’s not a psionic issue so it can’t just be pulled out.