Eggman Island

In the middle of the ocean a small, once uninhabited island stood, surrounded in metal walls and gates, battleship guarding nearby, painted red and yellow and with the logo of the Eggman Empire. The island itself had been turned into a giant factory, containing Egg Pawns guarding the insides of the walls. Suddenly, a blue blur came dashing into the walls, making holes in them. The Egg Pawns scuttled everywhere, searching for the best battle advantage points.

"Intruder alert! Intruder alert!" the alarm went off. "Subject: Blue Hedgehog, heading for the main core! Repeat: subject: Blue Hedgehog, heading for main core. This is not a drill!" Sonic boosted straight into the wall of the main tower, breaking it down. He stopped in a giant circular room with a giant shaft in the middle with a tower and hid behind some metal containers and got out his radio.
"Tails, this is Sonic, do you copy?" Sonic said.

"Yeah, I copy." Tails responded from the other.
"Breaking into this place was too easy! Run on the water, parkour up the main gate, jump to the docks on the edge on the island, then boost straight to the tower, destroying everything in my past! I was too fast for any of the bots' reactions!" Sonic bragged.
"Don't get cocky, the place is bound to become a shoot out once those Egg Pawns find you." Tails said. "Just focus on getting to the main core and planting those bombs…" Sonic put away the radio, and heard gunfire coming from inside the same room. Egg Pawns aimed for his location. Sonic jumped out of his cover and down a giant shaft in the middle of the room, down to the bottom of the building, where the main core was, which was the bottom of the tower inside.. Sonic planted the bombs and turned on the radio again.
"Bombs planted, pick me up at the top of the tower." Sonic ordered. Just as he was about to begin parkouring up the tower, when he noticed that wrapped around it was a giant mechanical centipede. It stared at him with it's 7 red eyes. Sonic smiled, homing attacking the head, then running up the tower, with the centipede giving chase. Sonic ran to the top, and smashed the ceiling, standing on top of the tall building. He saw the Tornado off in the distant, coming towards him. Sonic waved to his best friends, but stopped as he heard the giant centipede smashed through the ceiling, destroying all roof, sending Sonic flying in the air. Sonic grabbed a back piece of the centipede, as it marched along the outer wall of the building. Egg Flappers, of the green cannon variety, moved closer to them, opening fire at both Sonic and the centipede robot. Most shots hit the centipede, sending it into a fit of rage, making shoot laser at anything flying near it and it run faster, causing Sonic to lose his grip. Tails shot down a few Egg Flappers and caught Sonic before his fell, with the Tornado's wing, both barely avoiding the laser fired at them.
"Thanks buddy," Sonic said, giving Tails a thumbs up. Tails flew further from the tower and pressed a switch he had, which activated the bombs, blowing up the main core, which caused a huge chain reaction to all power cores on the island, making the island blow up, leaving it as nothing but a crater in the middle of the ocean.
"Alright! We did it!" Tails laughed in joy, high fiving Sonic as they flew away.

Chaos Island

The Tornado lands on an airstripe near a small village. An old frail chinchilla, where a grass crown and holding a walking a stick walked up to them.
"Did all go well?" he asked.

"Yeah, the base was destroyed," Sonic said, jumping out of the plane. "I'm sure that'll set Eggman back a bit."
"Oh happy days!" the chinchilla said, jumping for joy. "My people are safe once more!"
"What's so important about this island, anyhow?" Sonic asked, as Tails jumped out of the plane.
"Surely you've seen the temple?" the chinchilla asked. "The giant structure our ancestors built, as well as what our village was built around?"
"Yeah, but what's in it?" Sonic asked. "The doors are locked."

"All we know is that it hold the ultimate power, but only to one who brings all seven Chaos Emeralds." the chinchilla explains. "We're unsure what the ultimate power is or any other details, since the text our ancestors wrote has been translated so many times."
"There is however a key to open the temple doors!" Tails explains. "It's just that no one knows where it is…"
"I see you've been doing your homework!" Sonic chuckles, rubbing Tails' head.
"Sonic, Tails? Do you copy?" Amy's voice came from the radio. Sonic got it out.
"Sonic here. What's up?" Sonic asked.
"I'm on West Side Island, at Mirage Saloon Zone, and I see an Egg Cruiser ship flying over!" Amy said. "It's one of the ships he had in Sky Troops during the Black Arms invasion."
"Tails and I will be right there," Sonic said, getting Tails and taking over in the tornado to Westside Island.

Mirage Saloon Air Space

Tails flew the tornado close to the Egg Cruiser, allowing Sonic to jump off and get onto the top of it. Egg Pawns came out of the ship, rushing towards Sonic, but Tails shot them with the Tornado. He transformed it into a walker, like the one during the Project Shadow incident. Sonic ran to the front of the ship, while Tails destroyed any Egg Pawns trying to get in the way.
"I'm picking up a signal, Sonic," Tails said. "They're trying to call for backup!"
"Consider the meetup cancelled!" Sonic said, spin dashing into the satellite dish on the top of the ship, destroying it. "Now to get inside, take control and deliver this ship to the G.U.N.. They could use it for something."
"Do not be fast with the delivery of this shipment." a high pitch voiced said. Out of a trapdoor, flew out an adult dark chao, with a robotic right eye, standing on a floating platform. They had a grin and their body was covered in a red cloak.

"Listen buddy, I'm not sure if you know me, but I'm the definition of fast!" Sonic bragged. "Also… you're a chao? That can speak?"
"Chox do not believe you are the definition of fast, which you are saying are. Unless Chox is missed something? Last Chox check, fast was not meaning of blue spiky hedgehog whom is stupid!" the Chao said. Tails walked over.
"And you are?" Tails asked.
"I am Chox. Chox is Dark Chao, had be found by the Eggmen!" Chox laughed, in their high pitched voice. "Now Chox finding you, here on the Eggmen's ship! Chox is seeing that blue and two are of wanting this vessel to crash! Allow Chox!" Chox laughed, getting out a ray gun with their right hand. They rapid fired at the ship's engines and flew away, as the ship started to fall. Sonic quickly jumped onto the Tornado, as Tails transformed it and flew off, chasing the falling Egg Cruiser.

"That thing is going to crash into Oil Ocean!" Tails said. "And if we can't stop it, Mirage Saloon will be done for!"