The moral of the story was that monsters aren't unconditionally evil like Star thought and that they were capable of being good.
It's pretty much a dead theory now, but I liked the idea that the wand had a mind of it's own and that it could be "awake" when held by an evil person which is why the wand looked more like Lobster Claws when he held it while good but lose that resemblance when LC held it while evil. Would have been cool if the wand itself was the final boss.
Tbh, I don't really like the direction they took with the monsters in seasons 3-4. In Lobster Claws, they had Ludo telling LC to "act like a monster" and when Star said "all monsters are evil," LC said that they "don't have to be" acknowledging that they were evil.
In Marco Grows a Beard, Ludo tells Buff Frog that he saved him from a life in the swamp and took in one of the monsters off the street. So we see that monsters live in poor conditions.
In "Is Mystery" they had the other monsters admiring Buff Frog for his skills in torturing people and the monsters were bragging about how evil they were.
When Moon visited the Avarians, Brudo said they were extra hard on Ludo to "toughen him up" so I imagine most other monsters had similar upbringings.
I thought Moon the Undaunted would put the lynchpin in all this by explaining why the monsters are so violent and wreched: She scattered the leaders of the monster armies and left them "without country or leadership." So I thought Season 3 would be about how monster society is basically a mad max world where the most brutal and violent monsters called the shots, and attempting to integrate peoples comprised mostly of brigands and barbarians with the comparably more docile and wary mewmans.
I also expected the monsters to be more suspicious of Star and her intentions. At least most Mewmans only fought monsters when there was a war going on, but Star used to like to run into the wild and beat them up just for shits and giggles..