The Fake Gustave is a villain from SaGa frontier 2, and the last possessor of The Egg. His true identity is unknown, as he acts more as a pawn of the Egg.
He first appears overseeing a battle between royal guards and a group of bandits claiming to be descendants of Gustave XIII. One of those bandits, mortally wounded, fall at his feet, saying he has a proof, to which Fake Gustave just dismisses, as it was just an ordinary Anima stone. He appears later at a bar, where he claims to be Gustave XIII, but everyone laughs, since he had white hair in contrast to Gustave's blonde hair, so he simply turns his hair blond with a mere tought, making everyone impressed. He asks the customers what else he needs to "be" Gustave, to which they reply Gustave had close allies whom he could depend on, so he simply leaves the place.
He later appears on the Quarrysite, following Sargon, who had gone there to find the source of monsters who were rampaging the land. He dismisses Fake Gustave's claim that he is gustave as a bad joke, refusing his aid when his friends Gretta and Watts grow suspicious of him. Sargon finds a strange puzzle room, but as he solves it a huge amount of Anima flows into him, turning his friends into slimes and making him fall unconscious. As he wakes up, Fake Gustave greets him, as Sargon pledges his loyalty to him, ecoming the first of his Edelritters, the Fire Lord.
Fake Gustave, along with the Edelritters, start a rebellion to take over Hahn Nova, Gustave's stronghold, challenging the forces of Count Charles of Jade. Charles underestimate the impostor, thrusting his forces against Fake Gustave in the Battle of Hahn Nova, while his son David attempts a peace treat with the other kingdoms. Fake Gustave wins the battle, killing Charles in the proccess. Charles's death allows David, new Count of Jade, to sign a provisional peace treat, asking for support from the other kingdoms to fight the impostor.
Meanwhile, Wil Knights, who had pursued the Egg through his life, learns that Fake Gustave is in possession of the Egg, deciding to go to Hahn Nova to investigate, along with his grandaughter Virginia and her friends. He senses the Egg's presence immediately, deciding to leave the place, since the Egg can also feel his presence. Indeed, Fake Gustave orders Sargon to take his troops and kill Wil, but he manages to escape.
David's allied forces finally charges against the forces of Fake Gustave in the legendary Battle of South Moundtop, but he is forced to wait for the arrival of the forces of the Duke of Laubholz. Fake Gustave, who also lost one of his forces which risked pursuit of another troop allied of David, decides to not risk witing and charges into battle. David's forces manage hold him down enough for Duke of Laubholz to arrive, allowing him to win the battle. David finally achieve peace among the kingdoms, turning Hahn Nova into a neutral zone.
Wil and his group, who were overseeing the battle from a distance, learn the Fake Gustave's body disappeared in the midst of the battle. Later or he is informed that fake Gustave and the remaining of his soldiers fled into the northern continent, so he pursues him, finally confronting the Edelritters and the Egg in the Final Megalith. It is unknown what happened of Fake Gustave's body, though it is safe to presume the Egg simply took total control over it and mutated it into the monstrous form it assumes for the final battle.