This story is based on this pic by Tigerfog: art/SegaSonic-Sunset-Showdown-112185195

I have adored this pic since i first saw it, i love the poses, the colouring, the dynamic nature of it. Everything.
After writing the oneshot i noticed some little things i'd included without noticing, like the TailxAmy fluff being inspired by the fact that while everyone else is staring at Shadow, Tails is looking straight at Nack and Amy.

"Drop the gun, Nack!" Shadow shouted. The ebony hedgehog stood, holding two 9mms, in a standoff with a purple weasel who now held a revolver less then 3 inches from Amy Rose's face. Nack smirked and leaned on his knee which stood atop Amy's Piko Piko hammer. Sonic, Tails, Cream and Cheese, Rouge, Espio and Mighty stared, frozen. All eyes on Amy, who was paralyzed with terror. Sweat rolled down the side of her face as she took in every contour of the gun aimed at her.
"You know I can't do that Shad." Nack called out, "We both know that in a fight with all of you guys here I don't stand a chance…this lil chika is my only bargaining chip."
Shadow bared his teeth, "Dammit, Nack. You're not walking away from this."
Nack laughed, "There is one way I can; Gimme your Chaos Emeralds!"
Rouge gasped, "Wha!? How do you know we have any?"
"Baby, please." Nack said smugly, "Besides the fact that you, a famous treasure hunter, can't not have at least one, I know you bozos are trying to gather them all to stop Dr Eggman for like the 50th time now. So my terms are simple; hand over all your emeralds and I let the pretty miss Rose here go."
Sonic's heart was stuck in his throat. What should he do? Even though he knew everybody had a say in this dilemma, he felt responsible for Amy's safety…but if they handed over the emeralds Eggman would definitely buy them from Nack and then nothing would stand in his way. Then his best friend Tails took the responsibility from him and answered, "We'll do it!"
"Tails, don't rush to a decision." Espio said
"Shut up! I know what I'm doing!" the young fox snapped back.
"Tails, listen to him." Shadow said calmly, "If you don't plan carefully, your life could end…in a split second." Shadow glanced at Sonic, who caught the glimpse and tightened his body in readiness. Unfortunately Nack saw the look too and immediately pulled the trigger, "Don't think I dunno what you're up to!" he yelled. As the fire spat from the barrel Shadow focused and induced Chaos Control, grinding time to a stop. Leaving only himself and Sonic unaffected.
Sonic ran as fast as he could, feeling sluggish as he fought the time flow. He grabbed Amy and dove out of the way as he felt time begin to speed up again. Just as he and Amy fell to the floor he heard 2 gunshots ring out. Sonic looked up to see the bullets from Shadows gun build speed, racing towards the still frozen weasel. As time returned to normal the first bullet hit Nacks gun, knocking it from his hand, the second bullet impacted Nack's kneecap and he fell to the ground howling and screaming in agony.
Everyone stood, silent for a moment, staring at both the bleeding Nack and Sonic and Amy lying on the floor.
"Are you ok?" Sonic asked. Amy nodded, still in shock, but conscious enough to enjoy the look of genuine concern she saw in the azure hedgehog's eyes. As everyone recovered, Tails wandered over and picked up Nack's gun. He stared at it, unsure of how to feel. He was overjoyed Amy was safe but something deep inside felt sick at the thought that it was Sonic and Shadow that saved her, yet again. He wanted his own chance to prove he cared for her…and he felt a building, almost overwhelming rage at the thought that the gun he now held came so close to murdering Amy.
Tails' eyes were glistening with tears as he turned to Nack, cocked the revolver and pointed it at his head. Nack froze, still wincing as blood poured out of his knee, but terrified of the young boy.
"Tails, no!" Sonic cried, but Tails already had his finger on the trigger, aiming right between Nack's eyes. At the last second the gun was snatched from his grip. He looked up to see Mighty staring down at him, holding the gun by the barrel.
With no remaining outlet for his emotions, Tails simply fell to his knees and sobbed. Nack let out a slight sigh of relief before swiftly being knocked out by a sturdy kick to the head from Rouge. Meanwhile Amy walked over to Tails, knelt down and hugged him. Tails instantly felt himself lost in the moment. While he still cried, he couldn't help but take her in, her smell, her touch. The idea of losing her hurt him more then anything else. Yet he constantly had to leave her fate up to Sonic…a flicker of anger rose again deep inside Tails at the that reminder; Sonic, the hero who must always save Amy, yet always rejects and turns her down. He was ungrateful and Tails wanted to prove that fact…but not now…now he was too weak…he could only hold the pink hedgehog close and pray that it wouldn't be his last chance…