Fantastic Science: Koura may be a user of this. While he clearly uses Black Magic (like animating the figurehead on Sinbad's ship), he also seems to use a form of chemical explosive to trap Sinbad in the cave on Lemuria.
Too Dumb to Live: YMMV on this, but Sinbad and his crew trying to sword-fight Kali, a statue made of stone (or metal, it's hard to tell). There is no way that swords could hurt it, and they have to knock it off a ledge to break it, anyway. Why not try to run or draw it out of the enclosed temple?
Uncanny Valley: The centaur's all-too-human screams unnerved some viewers.