Thundarr the Barbarian (1980)

S02E01 Wizard Wars

Wizard Skullus has taken control of the villagers residing in a desolate oil refinery, forcing them into servitude to wage war against his rival, the malevolent wizard Octagon. With Skullus's soldiers at the helm, the oppressed villagers are pushed to launch an assault on Octagon’s fortress, caught in the crossfire of their masters' bitter rivalry.