The Blue Priest is an inhuman creature with sorcerous powers who serves the goddess Hera.
He leads Hera's cult of warriors to claim the city of Troy (Not the Troy of Homer's Iliad) when their king refuses to sacrifice his daughter to Hera's sea serpent.
When the young princess Deianeira is sent away on exile, the Blue Priest pursues her. She believes him to be her protector, but when Deianeira joins Hercules on his mission to free Troy from Hera's possession, the Blue Priest summons Hera's sea serpent to devour them both.
Hercules kills the sea serpent by punching his way out of its stomach and squeezing its heart. As it dies, the monster regurgitates Hercules and Deianeira, and they are washed up on the shores of Troy.
Once there, Hercules teaches the exiled townspeople to fight so they can reclaim their homes, but Deianeira fears she is leading them all to their deaths. She prays to the Blue Priest for guidance, and he summons her to Hera's temple.
Hercules leads the townspeople to attack Troy, and they fight Hera's cult members while Hercules heads off to rescue Deianeira from being sacrificed.
Hercules defeats the Blue Priest and cuts his head off, freeing the city and the princess from Hera's grasp.
Sometime later, Hera resurrects the Blue Priest and gives him the task of disrupting the wedding of Alcmene, Hercules' mother.
The Blue Priest employs an army of merceneries and thugs to act as servants at the wedding, while he summons another sea serpent, the monster Perfidia.
At the wedding ceremony, Perfidia devours Hercules and Jason (the groom) while the thugs battle with their family and friends.
Perfidia is attacked by another sea monster, and Hercules kills Perfidia by punching through its stomach and snapping its spinal corde.
When the Blue Priest realises he has lost, he is pursued by Hercules' brother Iphicles, and Iolaus. The Blue Priest runs to the edge of a cliff and prays to Hera for protection, but she ignores his plea and his body is dashed to death on the rocks below.