Found The Black Cauldron on DVD in Giant Eagle today. Far from a cinematic masterpiece, but I'd been trying to find it on Netflix or Hulu for awhile for nostalgias. Watched as kid, forgot most of it. But now I can know its hilarious awfulness.
Plot is that basically Skeletor wants the titular Cauldron cuz it was forged from the soul of Sauron and can give him an undead army, kid who is a farmer of psychic pigs is supposed to keep psychic pig away from Skeletor so it won't tell him where cauldron is, but kid fails so hard he might as well have just walked up to the dude and handed it over, by playing pretend while it wanders off and then wasting time with a talking monkey thing.
Then right before psypig gives up the location kid uses plot armor to grab psypig and run off in the middle of Skeletor's army barracks, then tosses psypig into the moat.
Gets captured, random princess breaks him out and he finds magic sword that was just lying around in the castle's crypt, then practically goes power mad while using it to escape. Note that they didn't get out because he was good at swording, or that the magic was powerful, they got out because Skeletor's army stood around being dumbfounded. This is a running theme.
So they all stand around in a forest, have a random fight cuz kid thinks he's a badass suddenly, and talking monkey thing gets them all sucked into a whirlpool. Here they meet some fairies who just so happen to know the exact location of the cauldron, who are all hiding right next to Skeletor's castle. One takes them to the swamp where the cauldron is cuz kid wants to destroy it, showing exactly zero knowledge of what fucking genre he's in. Here they break and enter into the house of three witches, who after another pointless fight where kid is super possessive of the sword he stole (the witches say he could be "the greatest warrior" with it, LOLNO) trades the cauldron for his sword and the witches tell him that cauldron is indestructible but can be deactivated if someone willingly climbs in, which is lethal.
Witches disappear along with their house and everything in it and Skeletor's army instantly appears to take the cauldron, and re-capture everyone but talking monkey thing. So Skeletor activates cauldron, gets like five skeletons out of it while bragging how no ones ever had such a awesome army, then talking monkey thing comes back and unties kid and princess, kid goes to try and jump in cauldron, but monkey jumps in first. Skeletons all fall down, Skeletor comes back to see wtf happened, cauldron starts sucking everything around into it, Skeletor tries to throw kid in cauldron, but ends up slowly moonwalking to it cuz no one can do anything in this movie without absurd failure, Skeletor dies, cauldron conveniently implodes and takes castle with it while our "heroes" escape.
Witches appear to try and take the cauldron, but "heroes" want to bargain, witches offer sword, but kid turns down asking instead to have monkey thing back. Witches say this is impossible, but then immediately do it anyway. Everyone lives happily ever after or something.