OK K.O.! Let's Be Heroes S02 E18 Crossover Nexus

"Let's start the show!"

In the Cartoon Network City, K.O. is summoned by the villain Strike who plans on eradicating all the heroes from the Cartoon Network Universe. Now K.O. must team up with Garnet from Steven Universe, Ben Tennyson from Ben 10 and Raven from Teen Titans Go! to stop him.