Jashin

is the god worshiped in. One of its followers is the Akatsuki member Hidan. Jashin, according to Hidan, expects that all followers of Jashin - so named "Jashinists" - bring nothing less than utter destruction and death. Hidan always used to pray to Jashin before a fight, asking for a "good kill." If he is unsuccessful, or is not allowed to kill, he prays for forgiveness.

When undergoing a sacrifice, Hidan changes appearance after ingesting his opponent's blood. His skin then turns black with white markings representing a skeleton (it could also be a Grim Reaper if you count his scythe as well), a symbol of absolute death. He draws Jashin's symbol in the ground in his own blood and stands in the center. This symbol is an equilateral circumscribed triangle (an upside down triangle with a circle around it). Once his sacrificial ritual takes place, any kind of pain or injury that Hidan inflict or recieve upon himself is also inflicted upon his sacrifice, be it a mere scratch or a pierce in the heart. However, this ritual can be dispelled if Hidan either steps or is forced out of the circle. This is technique is called "Curse Technique: Death Controlling Possessed Blood."

Hidan is the "successful experiment of the Jashin religion's secret jutsu", which makes him become immortal. He uses this advantage to otherwise fatally injure himself while he is linked to his opponent in order to kill them. We see this during the fight between Team Asuma and Kakashi vs Hidan and Kakuzu.