2004's Godzilla Final Wars is famous for its expansive roster of monsters. The final boss, Keiser Ghidorah, was an interstellar kaiju brought to Earth by the Xiliens to end Godzilla forever.

Each of the Godzilla Challenger Series decks includes a different Mechagodzilla card. These can't lead the deck, but as both Rodan and Ghidorah have the Void attribute, you can run Mechagodzilla ...