Curse Devil

Aki and Santa Claus have contracts with this devil, and Aki refers to it as Curse. By driving nails into the opponent's body and paying a price, its ability activates, cursing the opponent to death. Aki possesses a sword shaped like a nail imbued with this power, and he uses it in battle when activating the ability. Aki's contract allows him to curse the target to death by stabbing them three times in exchange for his lifespan, making it his trump card. Santa Claus has different conditions. While it can certainly kill the opponent if successful, it is less effective against weapon humans who can revive after death.