The story mode for Hellfire Fighters. Nuff said.
Tournament of the Stars
At Rosalina's Tournament of the Stars, the first battle is about to begin. It's Mario, the Mushroom Kingdom hero, versus Superman, the Man of Steel. After the battle, the winner revives the loser's trophy, but then an army of robot koopas arrive. Mario and Superman take a fighting stance, but the two fail to notice the mysterious emblem on the Robo-Koopa's foreheads.
After the Robo-koopa battle, the two see Bowser's airship heading towards the stadium. Bowser's airship picks up Rosalina, as Mario uses a cape feather and the super duo heads towards Bowser's airships.
Dipper and Mabel Pines are in bed, when they hear loud, frightening screams of pain. Dipper and Mabel walk out and see a portal, and the screams are coming inside of it. Dipper bravely goes into the portal, with Mabel following him, as the portal closes behind them.
After going through the portal, the two realize they are in a digital spectrum.They notice screams are even louder then before. The two look to their right, and see Alpha, who seems to be glitching out, which is why he was screaming. After a while the glitching stops, and Alpha falls on the ground. Dipper helps him up, but the trio notices glitch monsters coming ahead. After defeating the glitch monsters, a portal out of the spectrum opens up, and Dipper, Mabel, and Alpha go through it.
Fantendo Character Jail
Donut Steel is taking Dream Boy into the Fantendo Character Jail. However, just as he is about to put Dream Boy in his cell, An IP busts in and saves him. Donut Steel beats them both easily, but then realizes all of the inmates of the Fantendo Character Jail were broken out! Donut Steel finds Unten's trophy and revives him. Unten said that the IP Donut Steel fought was getting help from some "wierd computer virus." Just as Unten says that, Donut Steel becomes possessed by XANA, becoming XANA Steel. Unten defeats XANA Steel and restores him to his original state.
Green Hill Zone
Sonic and Tails are chillaxing in Green Hill, when they see Bowser's airship overhead. Soon, it starts raining Robo-Koopas down on them. After defeating the Robo-Koopas, they see Mario and Superman land down. The four decide to team up, but they get ambushed by Badniks! The Badniks seem to have the same symbol that the Robo-Koopas have. After beating the Badniks, the four get into the Tornado and head off.
Elder God Temple
At the Elder God Temple, Raiden is discussing the invasion of XANA with the Elder Gods. Soon, the temple is invaded by more of XANA's robots. Raiden tries to defeat them, but then Thor teleports in and helps him. Then the two thunder gods see Bowser's airship and teleport inside it.
At ;Lavendera, Nylocke is training when he sees a group of XANA possessed players ambush him. After defeating them, Nylocke sees a portal open up, and Alpha, Dipper, and Mabel come through. Then the group sees a portal and decides to split up: Alpha and Mabel will go through the portal, while Nylocke and Dipper will stay in ;Lavendera.
After a while, Nylocke and Dipper find Rockoon. After defeating Rockoon, the two continue through ;Lavendera until they find a mysterious portal and go through.
On Bowser's Koopaship, Bowser meets with Eggman. Bowser puts Rosalina's trophy on a stand, when suddenly, Mabel and Alpha bust in. Bowser turns Mabel into a trophy, and Alpha takes down some more henchbots with help from Raiden and Thor, before they escapes the airship and meets up with Unten and Donut Steel.
Nylocke and Dipper land in the Mystery Shack, where they find Gideon storming the Shack with an army of Gnomes. The two try to hold them off, but suddenly, Mario, Superman, Sonic, and Tails come in to help. After the defeat of the Gnomes, Gideon runs away into Bowser's Koopaship. The six continue to follow it in the Tornado.
Luigi is scoping out the Mansion for ghosts, but he is ambushed by Boo. After beating Boo, Luigi sees XANA is controlling all of the ghosts in the area. Soon, Data busts in and helps, defeating the ghosts. Luigi and Data decide to escape the area before XANA can control them. They escape the mansion and meet up with Alpha, Raiden, Thor, Unten, and Donut Steel.
Unten's group makes it to Fantendo HeadQuarters, where they decide that they should gather a team of Fantendo heroes to help. Flip, Mika and Dream Boy decide to help. The group reluctantly lets Dream Boy join when they are attacked by Pilf. After defeating Pilf, the gang sees a bunch of glitch creatures attack. Inevitably, they are all being controlled by XANA. Suddenly, Ashura glitches in and takes them all down. Raiden teleports the group out of the area, as it has been infested with glitch creatures.
Johnny Cage is at a film studio, where he meets Bruce Banner, who was hired to be the film cameraman. After a while of filming, Trixie comes in and wrecks the place. Bruce Banner turns into Hulk, and him and Johnny Cage fight off Trixie and her minions. After a while of fighting, one of the minions plants a bomb! Luckily, Iron Man flies in and saves Johnny Cage and Hulk.
The group lands in Nostalgia Critic's room, where the Nostalgia Critic is reviewing another crappy movie. Iron Man asks NC to help, and he reluctantly joins.
Ganondorf's Trophy Dungeon
In a cutscene, it shows Link knocking on the door of Peach's castle. Peach answers, and Link says that he needs her help, and they get on the Loftwing and head towards Ganondorf's Trophy Dungeon.
Once they land in the dungeon, Link finds Ganondorf and Zoroark guarding the dungeon. Link and Peach defeat the two, and revive the trophies of Rosalina, Mabel, Zelda, Kirby,Hobbes, Pinkie Pie, Lucario,and Villager. Soon, Iron Man, Hulk, Johnny Cage and NC pick them up on the Helicarrier.
Donkey Kong is asleep in his treehouse when he wakes up and realizes his bananas have been stolen again. DK starts to have a panic attack, and Cranky Kong has to calm him down. After DK is calm again, he goes to save his bananas, with Cranky reluctantly following.
The two kongs find King K Rool and defeat him, but it turns out he didn't have the bananas either. Suddenly, Bowser's Koopaship comes in, and it has a large net on the back of it containing TONS of bananas. DK starts to attack when they get teleported away in a bright light.
Calvin is looking for his buddy Hobbes in his backyard, when suddenly he is greeted by Pit, who tells Calvin that Hobbes is safe, and they need to protect the yard from hostile forces. Calvin and Pit start holding off the foes, when suddenly out of nowhere, Derpy Hooves drops in, and crashes into most of the enemies. Calvin asks Derpy what happened, and Derpy says "I was just delivering the mail!" Suddenly, Calvin, Pit, and Derpy are teleported away in a beam of light.
Soon, a cutscene shows. Zim, Gideon and Trixie are working on building a robotic body for XANA to possess. Soon, after the body is finished. XANA's symbol appears on the head of the robot, and starts to glow. The screen then fades to black.
Mario wakes up, when he finds Superman, Sonic, Tails, Nylocke, Dipper, Donkey Kong, Cranky Kong, Calvin, Pit, and Derpy Hooves in a strange sky area. Soon they get ambushed by Gnomes, Robo-Koopas, Badniks, and all the other enemies. Soon, after a long fight, the group sees Palutena, who congradulates the group by increasing their strength. Then, Luigi, Data, Alpha, Donut Steel, Unten, Flip, Mika Sho, Dream Boy, Ashura, Link, Peach, Rosalina, Mabel, Zelda, Kirby, Hobbes, Pinkie Pie, Lucario, Villager, Iron Man, Hulk, Johnny Cage, and the Nostalgia Critic are teleported in. They are all confused about what's going on, and Palutena explains that they most go to fight XANA at Final Destination.