Mechtavius Destroyer first appeared in Season 22, where he fought against Gohan. Despite having the power of 4 Mechtogan, Mechtavius Destroyer was defeated. Mechtavius Destroyer reappeared later on to battle Spectra Phantom, and told the villains not to waste time, foreshadowing his next appearance.
Later, during the Season 22 finale, Mechtavius Destroyer was revealed to have been behind the events that occurred during the Neo Smash Champion Tourney. However, Mechtavius Destroyer is ultimately defeated by Gohan.
In Season 23, Mechtavius Destroyer destroyed most of the multiverse and was invincible for the majority of the season, but is killed by Dragonoid Destroyer during the finale.
In Season 24, Mechtavius Destroyer killed the remaining Heroes of Legend, with the exceptions of Naruto Uzumaki, Goku, Sonic the Hedgehog, Gohan, Sasuke Uchiha, and Fabia Sheen, as well as all the Bakugan Battle Brawlers' Bakugan with the exceptions of Drago, Reptak, Aranaut, and Infinity Helios. Fortunately, this event was undone when Drago killed Mechtavius Destroyer in the past. Later, the Heroes of Legend fought Mechtavius Destroyer in the past once again and killed him again. Shortly after this, Mechtavius Destroyer fought every hero and villain at the Center of Time and Space, but was defeated. Mechtavius Destroyer later fought against Fleetway Super Sonic but was defeated. Mechtavius Destroyer did not reappear until after Drago and Razenoid's battle against the Wolverine Bakugan and the Iron Man Bakugan, where he went to Smash City and destroyed it. From this moment onward, Mechtavius Destroyer solely belonged to Coredegon as his ultimate transformation. Mechtavius Destroyer also went to New Vestroia and killed the Battle Brawlers' Bakugan once again, and then proceeded to destroy Vestal, Neathia, and Gundalia. However, Mechtavius Destroyer was stopped in his tracks when Sonic sealed him inside the Omni-Viewer. To ensure Mechtavius Destroyer wouldn't return, Sonic threw the Omni-Viewer into the waters of Green Forest. Mechtavius Destroyer is later released by Nazo for reasons unknown. After Nazo defeats the Heroes of Legend, Mechtavius Destroyer emerges from the water, declaring that he has won while he initiates his final plan. However, Mechtavius Destroyer is killed by the Heroes of Legend.
Due to Metal Sonic destroying the barriers of time and space, Mechtavius Destroyer is revived and he tries to kill Classic Sonic, but is stopped by Modern Sonic. Mechtavius Destroyer also has his original color scheme back, meaning that this is the original version of Mechtavius Destroyer.
In the second arc of Season 25, Mechtavius Destroyer is linked to Mephiles the Dark, resulting in the loss of his color. However, he later severs this link thanks to the unintentional assistance of Mario, and revives his creations, which were fused with him, in the process. However, Mechtavius Destroyer is severly injured by the Ultimate Fusion. Later, Mechtavius Destroyer is fused with Samus Aran by Dr. Eggman, and attempts to prevent the heroes and villains from leaving Universe-616, which has become unstable due to the recent time travels and Drago's death, but fails to stop them. Mechtavius Destroyer then follows the residents of Universe-616 to Earth-T, where he manages to seperate from Samus by manipulating the villains of that reality into getting energy for them. However, before breaking off his partnership with Samus, Mechtavius Destroyer provides Samus with Stardust Dragon's energy, which she tried to absorb a long time ago but never got to it, while stating the end has come. During the battle against the heroes and villains, Mechtavius Destroyer manages to absorb the power of the Lumas. Mechtavius Destroyer later betrays Samus and Mephiles due to Samus getting on his nerves, and proceeds to kill and absorb both of them. Following this event, Mechtavius Destroyer's size increases massively. Later, Mechtavius Destroyer, Evil Way Big, and Dry Bowser engage in a fierce battle against the heroes and villains as well as the inhabitants of the Internet once again, and pushes everyone to their limits due to Mechtavius Destroyer's immense power. However, Mechtavius Destroyer begins to get overwhelmed after the Lumas bring all 754 Power Stars to the heroes and their allies, who become powered up by the positive energy of the Power Stars. Mechtavius Destroyer is then obliterated permanently by the Heroes of Legend.
Unfortunately, Mechtavius Destroyer left a seed within Lena Isis, who (with the help of Dry Bowser and Ultimate Kevin) proceeds to gather energy to revive Mechtavius Destroyer with even more power than before. Despite being delayed by Vilgax, Mechtavius Destroyer is fully ressurected by his allies, only this time with the energy of the Power Stars.
Later, Mechtavius Destroyer becomes the Herald of Diagon, but betrays him to steal his power. After absorbing Diagon, Mechtavius Destroyer's power increases dramatically, but is defeated when he is betrayed by Ultimate Kevin, who absorbs Mechtavius Destroyer's energy only to have it drained by Darkstar and Vilgax.
Mechtavius Destroyer is finally killed at the end of Season 26 along with the other villains. Unfortunately, the Internet would recreate the villains shortly after this, ironically, to entertain the heroes, who wanted him dead for good. At the end of Season 27, Mechtavius Destroyer uses Psyphon's energy absorption machine to absorb the other villains and gives their energy to Sasuke Uchiha, corrupting him once again as part of the Grand Design.
During the finale of the first arc of Season 28, Mechtavius Destroyer is revealed to have been behind everything that has happened since Season 7, and engages the heroes and villains in a final battle with the fate of the multiverse on the line. However, Mechtavius Destroyer is ultimately defeated for good by Naruto's Rasenshuriken, which was enhanced by everyone's energy, and Gohan's Kamehameha after Sasuke distracts him with Kirin. Mechtavius Destroyer later helps the Heroes of Legend escape from the Home For Infinite Losers, but is unable to escape with them. However, Hades allows Mechtavius Destroyer to leave due to his affiliation with Vilgax and the League of Villains. During the finale of Season 28, Mechtavius Destroyer is finally killed by Goku's Super Multiversal Spirit Bomb.
In Season 29, Mechtavius Destroyer appears less frequently. During the Grand Finale, Mechtavius Destroyer finally makes his true comeback, as he declares a full scale war on the multiverse. During this war, Mechtavius Destroyer is fully ressurected and battles the Heroes of Legend and all their friends and foes several times, but gives them time to rest up since a continuous battle would take several days, while also attempting to gain access to the bedroom, which is the only place Mechtavius Destroyer hasn't destroyed yet.
Mechtavius Destroyer is finally killed for good at the end of The Grand Finale, and is imprisoned in the deepest depths of the Home For Infinite Losers where he can never escape. However, Mechtavius Destroyer escapes the Home For Infinite Losers in Season 30, where he destroys Station Square, sends the League of Villains to the Doom Dimension, and absorbs the zombies (excluding Colonel America, Zombie Daredevil, Zombie Nova, Zombie Mario, Zombie Wario, and the Galacti) in the process. However, Mechtavius Destroyer is prevented from heading to New Vestroia by the Heroes of Legend and their friends, who have overcome the Phazon Corruption that affected them. Mechtavius Destroyer is subsequently vaporized by The Creator's Triune and Dragonoid Destroyer. Since he was still dead, Mechtavius Destroyer is erased from existence forever. However, Mechtavius Destroyer is later revived by Ryuga and his allies, and begins to initiate the final phase of his plan for recreating the universe in his own image. Mechtavius Destroyer is truly killed for good by the Heroes of Legend at the end of Season 30. However, Mechtavius Destroyer returns in Season 31 due to his components never making it to Other World, and later reappears to fight Princess Peach. After defeating and turning Peach into a trophy, Mechtavius Destroyer begins to initiate his final plan by ressurecting the Halberd and using the Impure World Reincarnation to reanimate his victims as foot soldiers. Aware of the fact the League of Villains will not cooperate, Mechtavius Destroyer activates the volcano on Volcano Island to get them to flee, and declares that with his enemies now divided, no one will stop him this time. Following the birth of Necrosis and the betrayal of the League of Villains, Mechtavius Destroyer becomes an anti-hero and an ally to the Heroes of Legend, but maintains his desire to destroy all Bakugan. However, after Giga Bowser is ressurected, Mechtavius Destroyer ultimately redeems himself before sacrificing his life to enhance the Smash Core. In Season 32, Mechtavius Destroyer is released from the Smash Core, and has returned to his destructive ways. However, Mechtavius Destroyer is ultimately destroyed by the Heroes of Legend.
Mechtavius Destroyer's components are revived in Season 33 by the Heroes of Legend, though Mechtavius Destroyer doesn't reappear until Season 34, where he teams up with Ganondorf and Tobi as part of his newest plan to destroy the Heroes of Legend, and later joins the Revolutionaries during the Dimensional War, but helps the Heroes of Legend and Creator's Triune defeat Midna, and disbands back into Coredegon, Slycerak, Exostriker, and Mandibor after defeating Midna before retreating with the Revolutionaries.
Mechtavius Destroyer's components are then destroyed in Season 40.
- Mechtavius Destroyer has a size inconsistency, as he is shown to be bigger than other Mechtogan Destroyers even when he hasn't absorbed energy. This is likely due to the size inconsistency of the Nomadic Mechtogan when compared to regular Mechtogan.