This is my ending to s/8362470/1/Broken

Tails and Amy began sobbing uncontrollably. Amy's only romantic interest, gone. Tails's best friend and big brother, gone. Knuckles's rival and friend, gone. Shadow's rival and friend, gone. Rouge's friend, gone. Knuckles just couldn't believe how Sonic could be so weak.
Eggman led Tails, Amy, Knuckles, Rouge, and Shadow out of the base, seeing as there are so many traps and robots that could be initiated if he let them go on their own.
Once they were out of the base, Tails began to speak.
"I can't believe Sonic's gone," Tails sobbed.
"Sonikku's gone," Amy cried.
Knuckles went to Amy and Tails to try to comfort them.
"It's ok, Tails, it's ok, Amy. We'll get through this," Knuckles said. Shadow and Rouge just stood there, thinking.
After a moment, Shadow spoke.
"My only rival, gone. He was the closest thing to me, and he's gone." Shadow said.
"How are we gonna react to this," Rouge said.
"I want vengeance," Tails said.
"So do I," Amy said.
"Will you help us, Shadow? You're the closest thing to Sonic we got," Tails said.
"Hmmph. Why should I help you? Eggman rules the world now. It's over." Shadow said.
"Sonic could cut through Eggman's defenses like a knife through butter. I'm sure you could do the same," Tails said.
"No thanks," Shadow said. Shadow began to walk away. Rouge flew right into Shadow's path.
"Look, I used to be a thief. And even I know what Eggman did was wrong. No one deserves death. And Eggman treated us so cruelly. We have to do something before he does this to the rest of the world," Rouge said.
"I fought with him against the Biolizard. I fought with him against Black Doom. I fought with him against Solaris. Never have I seen him so weak. Luckily, I have a chaos emerald." Shadow said. "Lets do this. Lets get vengeance for Sonic."
Tails grabbed a tattered flag of the United States of America.
"For Sonic!" Tails yelled. "And the USA!"
"USA! USA! USA!" They all exclaimed.
Shadow then used a chaos spear to break the door of Eggman's base.
Suddenly, robots began spewing into the hallways, headed towards the breach. Shadow prepared his homing attack, then fired it at the robots. One by one, the robots fell. Tails, Rouge, Amy, and Knuckles followed. Knuckles used his fists, Amy used her hammer to defend Shadow's sides. Tails and Rouge followed.
They ran through long hallways, up long staircases, through long corridors. Suddenly, they ran into the room where Sonic died. Metal Sonic was still there.
"What is this?" Metal Sonic sneered. "You came back to die? So be it."
Shadow used a chaos spear to attack Metal Sonic. He missed.
"Go! I'll hold him off! Find Eggman!" Shadow yelled.
They all listened to Shadow. Eggman was still staring at Sonic's dead body, when suddenly, he noticed Shadow fighting Metal Sonic.
"Hmm? What's this?" Eggman wondered.
Suddenly, Knuckles found Eggman.
He's hiding behind that thick glass! Charge! Knuckles and Amy flew ahead while Tails and Rouge watched their backs.
Knuckles began to punch the thick glass, while Amy grabbed her hammer and whacked at the glass. At first, their attacks did nothing.
"They won't get through the glass." Eggman thought to himself out loud.
Meanwhile, Shadow and Metal Sonic were locked up in a tense battle. Shadow gave Metal Sonic a homing attack, followed by a Metal Sonic counterattack. Both ended up on the ground. Shadow and Metal Sonic got up quickly. Shadow sent a chaos spear towards the thick glass Knuckles and Amy were attacking. Although this caused a crack in the thick glass protecting Eggman, this let Metal Sonic slam Shadow to the ground hard.
"Give up, yet?" Metal Sonic sneered.
"Fat chance," Shadow sneered back. "Chaos blast!"
Suddenly, a white light began expanding from Shadow. Metal Sonic didn't understand what it was, and was enveloped by the chaos blast. Eggman knew what it was.
"Oh no. I gotta get out of here!" Eggman yelled.
But then the thick glass protecting Eggman, which had been cracked, broke. Knuckles and Amy stormed into the room Eggman was in and ran after him, catching him easily.
"For Sonic!" They yelled.
Knuckles threw Eggman onto the ground and punched him in the gut, killing him instantly due to brute strength. He punched Eggman so hard that his fist went into Eggman, then came out of his back.
What remained of the thick glass protected Tails, Amy, Knuckles, and Rouge from the chaos blast.
When the chaos blast ended, Shadow lay on the ground. Knuckles walked up to him with Eggman's body, blood pouring out of it. Knuckles's fist carved through Eggman's body like butter, so there was a hole where his stomach and part of his spine was supposed to be.
"For Sonic." They all said.