- Season 2
Schwarzwald attempts to spread terror by showering the city with the foretelling of his latest declaration of truth and the discovery of a sand dragon megadeus, known as the Leviathan. Roger is hired by Alex Rosewater to track him down and foil the impending doom that awaits Paradigm City. After Dorothy takes piano lessons under R. Instro, he invites her to a church where he is now an organist. Roger finds a recovered megadeus at the end of a tunnel underground. This megadeus, revealed by Alex, was the Big Duo that was wrecked when Roger was battling Schwarzwald from before, but now it will be modified using the wreckage of another megadeus, making it vastly more powerful. The city is being tormented by the Leviathan, and Roger is unable to use his communicator wristwatch because he is in an electromagnetic field. Dorothy tries to resist having to link herself with Leviathan, yet the Big O suddenly comes out and fights back. Roger, reaching the megadeus with Dorothy, then destroys the Leviathan. Angel later tells Roger and Dorothy that Schwarzwald was dead long before the Leviathan wreaked havoc upon the city.
- Megadeus: Big O, Leviathan (Megadeus), Big Duo, Foreign Megadeus, Archetype
- The artwork on Schwarzwald's flyer is a reference to H. P. Lovecraft.
- The artwork on Schwarzwald's flyer is by William Blake: "Behemoth and Leviathan".
- Angel says that Schwarzwald was dead before "Enemy Is Another Big!"