Sonic ran along the abandoned sidewalk through Park Avenue as destruction rained from above. Eggman wasn't making it easy this time, but that wasn't going to stop him.

"What the heck!? A whole army of Death Egg Robots!?"

That was his ally Vector speaking over their extended radio system. "Oh no!" came the voice of Charmy, another ally, "There are so many of them!"

They weren't lying, that was for sure. The city Park Avenue was located in was in ruins because of the huge army of robots that Eggman had unleashed on the world. The group of heroes were completely blindsided by his sudden rise to power, but that only spurred them on to fight harder. Brought together by their common goal, they banded together to form the Resistance and fight back against the forces of the Eggman Empire.

"Hurry, Sonic!" came the voice of Silver, another ally. "We can keep them in check, but not for long."

"That'll work!" Sonic replied as he busted another robot. "I'll find Shadow and be back in no time!"

As he continued running, he felt an uneasy feeling in his stomach at the mention of Shadow's name. Many of his friends were dependable allies who he could count on in dark times like these. He usually had an easy time knowing who was his ally and who was his friend. But his greatest rival was a different story. Shadow didn't align himself with anyone but himself. If anyone else just so happened to share a goal he had, then he would consider working with them, regardless of which side they were on. This made him a deadly wild card, which was why Sonic hoped he could find him in time to recruit him to the Resistance.

"This many Death Egg Robots?" came the voice of Knuckles. "Come on, seriously!?"

"I'm not one to complain," came Vector's voice, "but that's a lot, right? Way more than we can reasonably take on."

By this point, Sonic had reached the destroyed city square, where several robots were aiming at him, ready to fire. Sonic braced himself for combat, but before anyone could make a move, several aquatic ninja stars rapidly slammed into the robots. They quickly malfunctioned and exploded. Sonic recognized the attack: Water Shuriken! He looked up and, not at all surprised, saw a familiar Greninja standing on one of the abandoned buildings, arms folded as it looked down at him. He gave the Greninja a thumbs-up and took off again on the path. Greninja swiftly followed. While it wasn't as fast as Sonic, this Greninja was still able to keep up with the blue blur, as its special form greatly increased its leg strength, allowing it to move even faster than the already fast normal Greninja.

"Sonic! Can you hear me?"

"Yeah, Amy!" Sonic replied. "What's up?"

"Listen! Shadow has been sighted! According to May, he's travelling above the city at high speed!"

May Maple was a friend of Sonic and co. and, subsequently, a member of the Resistance. She had a close connection with Shadow. Maybe we should've sent her to find him Sonic thought. Then again, without super speed, she wouldn't be able to catch up with him. Hoping he could find Shadow in time, Sonic slid along a twisting rail, with Greninja following him.

"The last sighting was just up ahead," Amy said. "Be careful, Sonic."

"I will," Sonic replied, completely serious. He ran down the sidewalk with more determination than before. Then he stopped.

And there he was, arms folded as he stared at Sonic.

"I've been expecting you," Shadow said in his trademark deep voice.

"Shadow!" Sonic exclaimed. "Thank goodness I found you. Listen, we need your help –"

"Lemme guess," Shadow interrupted him as Greninja arrived overhead, looking down at the confrontation that was taking place. "You want me to help you stop the doctor."

"You know it," Sonic said. "We could really use your help. Eggman's really not pulling any punches this time. –"

As he tried to negotiate with Shadow, someone else walked towards them, hidden in an unseen alley. He clutched his arm in pain from an earlier confrontation, although it was starting to heal. A yellow, mouse-like creature was perched on his shoulder. He came to the opening of the alley and saw the two rivals talking.

"Looks like Sonic found Shadow," he said. "I hope he can help us."

"Pikachu," his companion, a Pikachu, agreed. At this, the Greninja above Sonic and Shadow started. It turned towards the young man and hopped down from its perch, coming towards him.

"Hey, Greninja," the boy said. "You holding up okay?"

"Ja," Greninja nodded.

"Good," he smiled. He turned back towards Sonic and Shadow. What he heard didn't make him optimistic.

"Shadow, I don't understand," Sonic said. "Why won't you help us?"

"That's no concern of yours," Shadow snapped back. His back was partially turned to Sonic, and his arms were folded. "I have my own goals, and I won't let you stand in my way."

"Are you really willing to stand by while Eggman takes over the world?!"

Shadow turned back to him with a firm frown. "The doctor isn't taking over the world, Sonic. He's already taken it over. Nothing is left."

"That's not true," Sonic shot back. "No matter how bad things get, my friends and I will always fight back against Eggman's schemes!"

"Hmph," Shadow scoffed. "Well if your plan is to be destroyed, then that's your choice, but it's a mistake: one that I refuse to make." Before Sonic could reply, Shadow vanished in a blue light.

"No!" the boy moaned on seeing this.

Sonic started on hearing his voice and turned towards him. "Ash?" he blinked.

"Hey Sonic," Ash said, coming out to him with Pikachu and Greninja. "I guess negotiations with Shadow didn't go so well, huh?"

"Pika," Pikachu sighed sadly.

"Nope," Sonic said with a shake of his head. "Guess we're gonna have to go on without him. Would've been nice if he'd said goodbye, though."

"Whoever said I was leaving?"

The two heroes looked up, startled by Shadow's voice. Shadow stood above them with a resolute expression on his face, and his gaze was fixed on the heroes. That was a bad sign for them.

"I just thought I'd introduce you to some of my friends," he growled as three familiar figures emerged from behind him. Sonic and Ash gasped in horror.

"Metal Sonic!" Sonic exclaimed.

"And Zavok!" Ash cried. "And…"

"CHAOS?!" the two of them cried in unison. The four villains, old and new, stared down at them menacingly.

"Shadow!" Sonic cried. "You don't mean to say you're siding with Eggman, do you?!"

"The doctor's power is far greater than you imagine," Shadow snarled. "Stay out of our way!"

"No way!" Ash retorted. "We've never given up the fight before, and there's no way we're going to stop now! Not when the whole world is at stake!"

"Ash is right!" Sonic shouted as well. "The Resistance stands for justice: we stand for what's right!"

"If you choose to stand in our way, then we'll defeat you like we always have!" Ash declared. "We've beat you before, and we'll do it again!"

You fail to understand…

Sonic and Ash started at the mysterious voice which caused goosebumps to crawl down their skin. "What?" Sonic said. "Who said that?"

"Pika pika," Pikachu breathed, looking above the four villains. Ash looked up as well.

"Oh man," he whispered as Sonic followed their gaze.

A mysterious, blood-red creature hovered in the sky, surrounded by a frightening aura. It looked similar to Sonic, but only one of its frightening yellow eyes was visible.

Our power he said as countless blood-red energy cubes materialized around him.

is INFINITE!

"Brace yourselves!" Ash cried as the mysterious villain assaulted them with its cubes. As though to confirm his earlier words, Shadow made no move to aid them. In this war between the forces of good and evil, he had one allegiance and one only:

To the Uprising.

If I had things my way, I would have written this during E3, like I did with the last two trailers. Oh well. Better late than never, I guess.