After Gravion unleashed its ultimate attack, the Zeravire threat was temporarily halted. Yet when the menace reappears abruptly, the Earth Gult and its trump card, the super robot Gravion, must defend the world once more. Meanwhile, the EFA plans to develop its own weapons to counter the Zeravire, the Grand Trooper. As they fight to repel the Zeravire, the people of Earth Gult and the EFA must safeguard their future, confront their pasts, and uncover the mysteries surrounding the Zeravire.