"Westopolis"
Shadow entered Westopolis "Mmmmm promised time huh? Well then time to go in and fulfill this promise." Shadow said.
He saw a GUN soldier being attacked by the Black Aliens it was flying above the soldier. Shadow using his homing attack on the flying creature the soldier was surprised Shadow saved his life.
Shadow ran into Sonic the Hedgehog "Hey Shadow long time no see." Sonic said.
"What are you doing here?" Shadow asked.
"Here save people of this city let's show the black creatures that we mean business." Sonic said.
The two began fighting the black creatures saving many lives as they can Shadow and Sonic saw a red cage with a force field surrounding it "Hey look there's a Chaos Emerald!" Sonic said.
"Look it imprisoned by the black creatures." Shadow said.
"Looks let we've gotta take 'em out to get the Emerald." Sonic said.
There was three bigger black creatures Shadow and Sonic used both their homing on the brutes weakening the black creatures until they fell "The bigger they are the harder they fall." Sonic said.
The cage opened Shadow collected the Green Chaos Emerald "With that Chaos Emerald you can unlock unlimited power." Sonic said.
They reached a intersection of the streets GUN soldiers were covering civilians Shadow found a weapon called "Shadow Rifle" it has the powers of a Chaos Spar Shadow fired it at the creatures saving the soldiers and civilians.
They took out 25 of the creatures Shadow and Sonic ran up a loopy loop Shadow and Sonic observed the city "These black creatures will destroy the planet if we don't stop them." Sonic said.
"It's clear about that." Shadow said.
They found the Blue Chaos Emerald like the green one it was in a cage Doom Eye appear "Shadow why attack our soldiers?" Doom Eye said.
"I don't take orders from you and I need the emeralds." Shadow said.
"Black Bull I summon you!" Doom Eye said.
"That's a big boy." Sonic said.
"Let's get this over with." Shadow said.
The two fought the bigger creature Shadow used his Shadow Rifle after noticing the creature was afraid of his blast however Shadow ran out of ammo Shadow found a purple aura inside a building Shadow touched it "Death to all who oppose me!" Shadow said.
He harnessed all of his power "Chaos Blast!" Shadow said.
He unleashed a massive blast taking down the Black Bull and collecting the blue Chaos Emerald "I won't let the black aliens gain these emeralds." Shadow said.
At GUN HQ there were reports of the black creatures attack a soldier came into the commutation room "The Black Aliens have attacked six major cities from around the world and every city has reported civilian causalities among Westopolis have received the most damage due to its weaken defense systems downtown Westopolis has been almost completely destroyed." the soldier said.
The commander had a angered look on his face "Unconfirmed sightings has also reported seeing a black hedgehog in Westopolis." the soldier said.
"Shadow?" the commander asked.
He turned around "Deploy the troops now! And if you find Shadow with the Black Aliens then kill them all!" the commander ordered.
"But sir reports have also sighted Shadow has saved several civilians and soldiers." the soldier said.
"I gave you an order soldier! He's evil and he's the enemy!" the commander said.
The soldier left the room "You can't fool me Shadow this time you're mine." the commander said, full bent on killing Shadow.
Sorry if my stories aren't that long I'm not really good at writing every detail into story.