EDIT: This chapter has been edited to make some things work better, and so that the story flows a bit better.
Okay, this is my first fanfiction... It's an adaptation of Sonic Colors, but as a crossover, with Mario and Luigi helping along the way. Sonic won't be doing all of the work this time around - Mario, Luigi, and Tails will all be important help to him. So, without further ado,
Super Mario Colors
Mario and Luigi touched down on the Comet Observatory in Luigi's Starshroom. Luigi was quite proud of his Starshroom, which was a bit bigger and faster than the Toad Brigade's, and was painted green with a yellow lightning pattern all over. After exiting the ship, Mario immediately threw up.
"Luigi?" Mario said calmly, not yet giving the hint to his anger.
"BUILD SOMETHING YOU CAN DRIVE!" Mario yelled at his younger brother, his temper showing.
"It's not like I didn't figure it out or anything," Luigi muttered sarcastically, a bit upset at his brother's words.
"I'm sorry, bro, you did figure it out..." Mario said, calming down, "Why is it so hard to stay angry with you?" Well, I know it's because you're my little bro, and we've been through everything together, Mario thought, but I know how much it means to you to try and make me proud.
"Maybe I'm just that awesome?" Luigi said heroically.
"Luigi, I know you have super-speed and IQ of 350, but that doesn't make you awesome..." Mario said jokingly.
"If you two are quite done, I must tell you what I've called you here for," a soft female voice echoed from the center of the Observatory.
"Oh, hi Rosalina," Luigi greeted the Princess.
"What do you need us to do?" Mario asked, "A great act of heroism?"
"More or less," Rosalina began to explain, "Recently, an alien race known as the Wisps have been disappearing. Their planet seems to have been kidnapped, even. They've been moved near a planet classified as Mobius."
"Why do you need our help?" Luigi interrupted.
"You two are needed because of your skills, Mario's amazing strength and resourcefulness, and Luigi's speed and agility. I cannot save the Wisps myself, as they are a massive source of energy called Hyper-Go-On energy, which is their life source. If someone with an evil intent were to use this power, the results would be catastrophic. The observatory is far too large to use to fight, and I am powerless without it, so I must send the two greatest heroes I know of to save them, and free their planet so that they may return to their rightful place with it. I'm sorry I don't have any more information for you, but now you must go. I wish you luck."
Bubbles of energy surrounded the Mario Brothers, and they shot off towards a new world, a new adventure, and new friends.
Sonic was running along the beach at high speed, which was easily his favorite thing to do. It helped him think about things and relax, sort of like meditation.
"Sonic!" a young, boyish voice urgently called from behind him.
"Tails? Is Eggman up to no good again?" Sonic asked his adopted little brother, who had flown up next to him with his tails.
"Well, I wouldn't say he's up to no good, per se, but he did build a giant space amusement park, there's an elevator to it about ten miles ahead" Tails replied a bit uncertainly. He may be a genius, but he's still a little kid.
"Really? Sweet! Let's go trash the place!" Sonic said, a bit too enthusiastic about getting to fight Eggman again, and sped off towards the elevator.
Tails slowed in his flying for a few seconds, a bit dumbstruck. "...That's not what I meant... I thought it would be fun to go on the rides," he said to himself, and flew off after Sonic.
When Tails caught up to Sonic at the elevator, he was standing next to the elevator car with the door open. "Can you believe Egghead left the keys in this thing? He's practically begging us to come up and trash the place!"
"Sonic, that's not what I-"
"No time Tails! C'mon, let's go!" Sonic interrupted Tails, grabbing his arm and pulling him into the elevator.
Okay, just so we're clear, Sonic's world isn't actually named Mobius. Rosalina simply uses that name to classify it. The prologue is more of an introductory chapter than anything, to define the Mario Bros' personalities. Since Sonic and Tails already have defined personalities, their part of the prologue is shorter. I'm open to new suggestions, if you have any.