Final Fury is a story arc in Super Smash Bros. Crossover. It revolves around the Heroes of Legend, the Heroes of the World, Team Melee, the Smash Fighters, the Bakugan of the bedroom, the Glitz Pit fighters, the League of Villains, the Eggman Empire, and Team OBOE's final fight against Mechtavius Destroyer in the past, present, and future.
Following the deaths of most of the Battle Brawlers' Bakugan and most of the Heroes of Legend, Drago went back in time and killed Coredegon, Slycerak, Exostriker, and Mandibor before they created BEN and Zombie Zelda. However, following Dr. Eggman's failed attempt to destroy the barriers that separate each timeline to bring the Nomadic Mechtogan to the current timeline, the Heroes of Legend and their Bakugan went back in time to before the rogue Mechtogan mutated and killed them again before recreating the multiverse. Unfortunately, Dr. Eggman escaped the White Space and ressurected the Nomadic Mechtogan, ultimately prompting the Heroes of Legend and all the friends they made over the course of the series to go to the past and future while one group remains in the present to erase Mechtavius Destroyer from existence. However, Dragonoid Destroyer teleports all the heroes and even all the villains and Mechtavius Destroyer to the Center of Time and Space to determine the fate of the multiverse.
After a long and hard fought struggle, the Heroes of Legend and their friends and foes unite their hearts and merge with each other, ultimately destroying Mechtavius Destroyer permanently. Afterwards, Dragonoid Destroyer unites all the fragments of the Smash Core, including the creepypastas, the weapons, the Sacred Beasts, the zombie plague, the Children of the Core (the Heroes of Legend's ancestors), Zorc's essence, Mechtavius Destroyer's essence, and himself to restore the Smash Core. Afterwards, the Heroes of Legend create a new world known as Planet Smash.
- The only characters that don't appear in this arc are Infinity Titanium Mecha Sonic, The Offspring of Zorc, and the Pecking Order, due to Sonic the Hedgehog erasing the Offspring of Zorc (except for Samus Aran, Bowser, and Zombie Reed) from existence, the Pecking Order never forming due to BEN and Zombie Zelda being erased from existence, and Mecha Sonic was destroyed after Metal Sonic was defeated while fused with him and the other Sonic robots.
- This arc has the biggest amount of characters, surpassing The Keys of Smash Arc, the Time Eater Arc, the Mechtogan War Arc, and the Fight to the Finish 2 Arc as the arcs with the most characters.
- This arc shows how dangerous Coredegon, Slycerak, Exostriker, Mandibor, and ultimately their combined form as Mechtavius Destroyer really are, as nearly every character in the series had to fight them.