Death Machines(1976)

Madame Lu has created three "Death Machines," a trio of martial arts experts who have been injected with a special serum, turning them into mindless zombies, capable only of murder, at Lu's command. Tasked with eliminating her enemies, the Death Machines go on a blood-soaked rampage, killing anyone in their path. After they massacre an entire dojo, leaving only one survivor, the Death Machines and Madame Lu herself become the targets of his vengeance...