After a valiant Thai boy is brutally murdered by a gang of archeological looters, his soul is joined with the Hindu god Hanuman, who teams up with Ultraman and his brethren against familiar Ultra-foes unleashed by a weather control experiment gone awry, in this influential Thai-Japanese co-production.

With an unquenchable thirst for the blood of virgin women, the wicked King Dark enslaves the brilliant Thai scientist Dr. Wisut to create an army of monsters to put an end to the chivalrous efforts of the cyborg warrior Kamen Riders. Where their efforts fail, can the Hindu god Hanuman help? Edited from Five Riders vs. King Dark (1974).