"Lord Jashin"
Hidan had absolutely no moral restraints regarding the people he killed; he considered slaughter a religious calling, and often took considerable pleasure in making his opponents' deaths as painful as possible. He firmly believed that shinobi were meant to kill and revel in violence, and found his village's deterioration into peace and disarmament to be infuriating, resulting in him slaughtering his neighbour before defecting. Hidan is sadistic and enjoys torturing his opponents. The amulet around his neck was a symbol of Jashin, and he used it to pray to his god before battling, requesting a good kill, or (when he was not allowed to) for forgiveness.
