Mutant Elfin is a main character in Super Smash Bros. Crossover. She was intially a protagonist, but as the series progressed, she became an antagonist, culminating in her becoming a rogue Bakugan, but later decides to truly join the heroes, as it is much more fun with them, though it is later revealed she was gathering DNA for Mag Mel's Evolved Razenoid. Like Drago and Preyas, Elfin can change attribute. Elfin is also a member of the Preyas family tree. Elfin had 700 Gs before evolution. Elfin's Battle Gear is Gigarth, the same as Preyas and her first Mobile Assault is a Jakalier she received from Drago to stop her whining about Preyas' Raytheus. She evolved into Minx Elfin when Drago transferred some of the power Zombie Giant-Man gave him in Zombie Giant-Man's last moments of life. She had 900 Gs. Elfin evolved into Mutant Elfin during the battle with Peach and Zelda of the silly Melee universe. She also spawned a Chaos Bakugan. Mutant Elfin's BakuNano is Sonicanon and her new Mobile Assault is Zoompha. Mutant Elfin now has 1000 Gs. Mutant Elfin's original Mechtogan was Venexus, though it appears Venexus was provided by Razenoid, as Mutant Elfin's true Mechtogan is Haos Accelerak. However, due to her evolution, Razenoid was able to brainwash Mutant Elfin to do his bidding by making her tell Tabuu to tell Sasuke and Mecha Sonic that Drago is vunerable and in the bedroom. She makes her first reappearance after Psycho Kirby is seperated from the others, still under hypnosis. Drago is shocked that Elfin is now a Darkus Bakugan, and swears to make the Dark Smashers pay. Later, during the Season 7 finale, Elfin snaps out of hypnosis and sacrifices herself to save Fox and Falco. Elfin is revived in Season 9 by Subterra Razenoid to help Drago fight Anubias, Sellon, and Mag Mel. In Season 13, Elfin becomes vicious due to Sasuke's rebirth. In Season 20, Mutant Elfin sees the devastation the Chaos Bakugan are causing, and she takes sadistic delight at the carnage, her heart having closed completely because of Sasuke's influence. Mutant Elfin later betrays Sasuke and joins Yami Bakura, seeing as they have much in common. After Yami Bakura is absorbed by Samus, Elfin mysteriously disappears. After the final battle, Mutant Elfin finds the bodies of Sasuke and Drago and begins laughing evilly. Mutant Elfin later reveals she turned Sasuke into an android and mutated Drago into Iron Dragonoid. Elfin also reveals that she was deceiving the heroes all along, and that the sadistic Elfin that emerged during the war was Elfin's true personality. Mutant Elfin then tries to reexert her control over Sasuke and Drago when they begin breaking free, but is unsuccessful. Elfin is then vaporized by Drago, who declares that Elfin is no friend, but scum that must be destroyed. Despite her death, Mutant Elfin is revived during the Time Eater Arc due to the timeline being damaged, therefore blurring the borders of the living and the dead. Mutant Elfin goes along with Tobi and Noah Kaiba in order to get revenge on the Heroes of Legend. During Season 21, Mutant Elfin denounces her evil ways, as she believes the heroes are much more fun than the villains. In Season 22, it is revealed that Elfin was the one who mutated the Razenoids, and is also revealed to have been hired by Mag Mel's Razenoid to "share his power" with his fellow Dharaks. Mutant Elfin is later betrayed by Mag Mel's Razenoid, who seemingly vaporizes her. Mutant Elfin later returns in Season 23 to help Sasuke battle against Wiseman, though her real reasons for doing so are unknown, as she claims she won't let anyone harm her battling partner. Later, Elfin goes to Evolved Razenoid's nightmare realm to rescue the Dark Heroes of Legend, where she reveals her backstory to her friends. After telling her friends her backstory, Elfin and the others are confronted by Mechtavius Destroyer, who has come to destroy them. Elfin is caught off guard by Mechtavius Destroyer's surprise attack on Sasuke, but remembering what happened to her brother (see backstory), Elfin's rage builds up to the point where she releases her excess energy to spawn a Mechtogan with her mutation. In Season 25, Mutant Elfin learns that her mutation has allowed her to spawn multiple Mechtogan of each attribute. Unfortunately, this information prompts the semi-ressurected Mechtavius Destroyer to order Tremblar to defeat her while surpassing her power level by 500 Gs, which Tremblar does by using all of his abilities, resulting in Mutant Elfin being captured by Mechtavius Destroyer. Later, Mutant Elfin is successfully reclaimed by Sasuke. At the start of Season 28, following Sasuke's recent corruption due to the Grand Design, Mutant Elfin decides to go to New Vestroia to protect the Bakugan there as well as her offspring. However, Mutant Elfin later assists her friends in the final battle against Mechtavius Destroyer and the villains, but is killed while protecting Evolved Razenoid from Mag Mel's Razenoid. Luckily, Mutant Elfin is revived after she is released from her stasis pod in Mechtavius Destroyer, and narrowly escapes from the explosion Fabia used as a diversion. At the end of Season 30, Mutant Elfin finally returns to Sasuke's side after Mechtavius Destroyer is defeated.
Prior to the events of the series, Elfin was a kind and sweet Haos Bakugan who wanted to get the other Bakugan to know each other better by putting them through experiments which will allow them to change attributes and stay in it for as long as they like. However, during an experiment on a Haos Harpus, the machine overloaded and caused the Harpus to explode, and the blast hit Elfin and a Haos Preyas, who was her brother. Elfin survived, but was mutated as a result, ironically succeeding in the experiment meant for other Bakugan. Unfortunately, Haos Preyas was killed as a result of the blast, and Elfin was so consumed by her guilt that she went insane, taking her experiments to sadistic levels. Deep inside, Elfin was filled with sadness at the death of her brother, and was hoping someone would help her revive him. Eventually, Elfin met Mag Mel's Razenoid, who was still a Dharak at the time. Dharak lied to Elfin that he had the ability to revive deceased Bakugan, but she had to gather several strands of DNA for him in return. Sometime before Season 3, Evolved Razenoid asked her to mutate the other Dharaks into Razenoids as well.
Elfin, Preyas, and Akwimos were the only Bakugan that have the same Battle Gear up until Elfin's evolution into Mutant Elfin.
As Minx Elfin, she had changed into every attribute except Haos and Ventus.
Mutant Elfin is the second Bakugan to spawn a Chaos Bakugan, and the first to do it willingly.
Mutant Elfin is the only other non-Razenoid beside Drago to spawn a Chaos Bakugan.
Elfin was originally a Haos Bakugan. The reason she was an Aquos Bakugan and a Darkus Bakugan for extended periods of time was because of the experiment that killed her brother. Elfin did this because she felt tormented in her true attribute.
It is unknown how Mutant Elfin survived being vaporized by Evolved Razenoid.
Mutant Elfin is the only non-Chaos Bakugan that has been seen in all attributes.
Mutant Elfin is the only Bakugan that has multiple Mechtogan.
According to Mandibor's scan, Mutant Elfin has 1200 Gs, which means that Mutant Elfin may have enhanced her power, since she originally had 1000 Gs.
Mutant Elfin is one of the few main characters to have given birth to an offspring during the series, the others being Drago, Fabia Sheen, and Tikal. However, unlike the other three, Mutant Elfin's children were not seen after their debut.