Blade of the Immortal (1993)

Manji is a swordsman in Japan who is regarded as the "Hundred Man Killer," for he had murdered one hundred innocent men. But there is far more frightening than this: he is actually immortal. This is the eight-hundred-year-old nun Yaobikuni's doing, who would place bloodworms that has the ability of healing almost every wound Manji has in his body. To compensate for the crimes he's done, he decides to kill one thousand evil men.