The Subspace Army implanted X-Bombs, Gooey Bombs, Smart Bombs, and Bob-Ombs everywhere.

At Jungle Hijinxs, Donkey Kong noticed that the Kritters took his bananas and he was going to teach them a lesson.

Donkey Kong: "Rgh...!"

DK knocked into tomorrow until they got pelted with peanuts and DK didn't know what happen when a monkey with Rocketbarrel Jetpack with a Peanut Popgun in his hands. It was Diddy Kong.

Diddy Kong soon got the Smash Ball and uses his Final Smash, Rocketbarrel Barrage as he flies around while firing his gun at the Kritters in his hands. Afterwards, Donkey Kong and Diddy Kong went to the jungle vine, and took a barrel cannons to leave.

Mario, Link and Kirby ended up at Willy's Castle and they met up with DK and Diddy.

Mario: "Well, if it isn't my good frenemy, Donkey Kong."

Link: "Hey, DK."

Kirby: "Hiiiiiii!"

Donkey Kong: "...?"

They all noticed a Full Moon and a shadowy figure on a cliff who had wind-flowing hair and somehow got a helmet on and opened his eyes and noticed Mario and the others and teleports down there. It was the super fighting robot, Mega Man.

Everyone goes to attack Mega Man one by one and Mega Man uses all his moves jam packed like special attacks, smash attacks, aerial attacks, tilt attacks, stranded attacks, and dash attacks.

Unaware of them fighting, there was a blue pegasus watching at the cliff and was amazed of the robots fighting moves.

???: "That guy's good. How will they ever beat him?"

Mega Man has two Metal Blades in his hands and throws one at Mario as he ducked.

Mario: "Whoa!"

Mega Man throws a second one at Link and he blocked it by using his Hylian Shield.

Link: "Whew."

They all came to him at once and Mega Man charged up his Down Smash, Flame Blast and they were passed out.

Mega Man woke them up and questioned them.

Mega Man: "Who are you guys and what are you all doing here?"

Mario explained everything to him even the Subspace Army and stuff. That's when Mega Man teams up with the Heroes.

Soon, the Yellow Devil shows up to face them.

Diddy: "What's that?"

Mega Man: "My old foe, the Yellow Devil."

Link: "Well, let's beat him and get out of here!"

Yellow Devil starts the fight by shooting lasers out of his eyes and Mega Man delivered the finishing move by using his Crash Bomber on him.

Mega Man: "Ha!"

???: "That. Was. AWESOME."

The Heroes turns around and meets the blue pegasus, Rainbow Dash.

Mario: "Rainbow Dash!? Where did you come from?"

Rainbow Dash: "Equestria. I heard that the Subspace Army is back. So I'm helping for my boyfriend, Sonic."

Mega Man: "You know Sonic The Hedgehog?"

Rainbow Dash: "Yes. Why? Do you?"

Mega Man: "Let's just that say that we go way back."

That's when five Changelings shows up and Rainbow Dash fights them. Rainbow Dash uses her special smash, Weather Control on one Changeling, uses her side smash, Rainbow Tornado on the second Changeling, uses her dash attack, Supersonic Dash on the third Changeling and uses her down smash, Tank on the fourth Changeling. Rainbow Dash see's the Smash Ball and grabs it. Rainbow Dash then uses her Final Smash, Sonic Rainboom and defeated all the five Changelings. Rainbow Dash goes back to the Heroes and does his victory pose.

Rainbow Dash: "Danger's my middle name! Rainbow Danger Dash!"

Mario, Donkey Kong, Link, Kirby, Peach, Zelda, Diddy Kong, Rainbow Dash, and Mega Man joined your team.