Gang-Si Training Center 1988 on netflix

Jeon Woi-ja, the wizard, uses evil spirits to serve his selfish desires. He opposes the Gang-si (frozen corpse) training center, Bubekjang Center, which educates wandering spirits and sends them away. Woi-ja picks the most evil corpses and sends them to the center in hopes of ruining it but without success. When his evil amulets fails to work he chants the eight signs of divination in hopes of getting rid of the gang-sis. But the gang-sis band together to fight Woi-ja and succeeds in reforming him and guiding him to a better path.