OK K.O.! Let’s Be Heroes featured five crossovers over its three seasons, and each of them was done differently. A Hero’s Fate concluded the story of showrunner Ian Jones-Quartey’s old webcomic, The Power is Yours brought is Captain Planet, Crossover Nexus unified four current Cartoon Network shows, Monster Party wrote Scooby-Doo and the Ghoul School into Enid’s backstory, and Let’s Meet Sonic… Well, we met Sonic.
It took three things for OK KO to make these crossovers well: a wild world where anyone can exist, no place on the power scale for guest characters, and a whole heaping nostalgia for the old shows being crossed over with. With those ingredients, OK KO made four excellent nostalgia trips and a great crossover for Cartoon Network’s current franchises.