OK KO Crossover Nexus Omega is a OK KO Let's be Heroes Episode. it's crossover episode features Garnet from Steven Universe, Ben from Ben 10, Raven from Teen Titans Go!, Phantasma from Scooby-Doo and the Ghoul School, Sonic the Hedgehog from Sonic the Hedgehog, Spear from genndy tartakovsky's primal, ilana from sym-bionic titan, Goku from Dragonball z & Sans from Undertale.
Strike want revenge on K.O. and his friends & planing to destroying the city, K.O. Need to get new friends to help and to stop strike again once more together.
- Ian Jones-Quartey as Pen / Radicles
- Courtenay Taylor as K.O.
- Michael Dorn as Strike / Strike Omega
- Estelle as Garnet
- Tara Strong as Ben 10 / Raven / Ilana
- Unknown Voice Actress as Phantasma
- Roger Craig smith as Sonic
- Aaron LaPlante as Spear
- Sean Christian Schemmel as Goku
- Unknown Voice Actor as Sans
- Ilana appearance is ok ko let's be heroes as a stone and reanimated cameo in Crossover Nexus but she's joins with KO, Garnet, Ben, Raven, Phantasma, Sonic, Spear, Goku & Sans in Crossover Nexus Omega.
- Russi Taylor, the true voice actress of Phantasma died in 2016, jul 26th.
- Phantasma's ok ko let's be heroes appearance first starting in Monster Party.
- Sonic the Hedgehog's ok ko let's be heroes appearance first starting in Let's meet Sonic.