Snow fell heavily from the dark night sky over Eggman's base. It was an ominous stronghold with high walls, and searchlights that remained vigilant at all times. Suddenly the alarms of the base wailed as a platoon of armed robots gathered in front of the main gate. they readied there guns as a streak approached them from the distance. It traveled through the snowy terrain at blinding speed, closing a vast distance in mere seconds.  All the robots could see was a black and red blur, before they all exploded at once. The figure stopped momentarily, revealing herself to be the ultimate life form, Shadow. The Female hedgehog destroyed the final robot at the gate by jumping on top of it, before she leapt high over the gate to the other side. She landed on the ground, unharmed by the height of her fall, before speeding off to the thick of the stronghold.
Eggman's mechanical forces were no match for the ultimate life form. They fell to pieces before her power, and in almost no time at all, she was speeding back out with her rescued friend, Rouge. She followed Shadow closely while clutching a strange, glowing sceptre in her hands. The black hedgehog blasted their way out of the base and excaped into the distance
"I'm really  glad you joined the G.U.N. Thanks for the rescue." Rouge thanked Shadow after their escape, they were calmly making their way to the designated G.U.N. rendezvous point. "It's not like you to get caught." was Shadow's only response. "You're so blunt." she teased. "Let's just get you to the rendezvous point so i can be done with my mission." Shadow insisted. "It's always all business with you. Don't you even want to know what this is?" She asked as she waved the sceptre around, "This is hy i was caught, after all."
Shadow merely rolled her eyes. "it looks ancient and it's glowing. That tells me everything I need to know. It's most likely dangerous, especially in Eggman's hands." She stated matter of factly.
"That's why I want it back." They both heard Eggman shout before a small army of robots dropped from above, and surrounded them. Eggman swooped in on his familiar hovercraft. It seemed heavily upgraded for combat, complete with the addition of huge robotic arms. "Rouge, and Shadow. It's been awhile." he greeted with a hint of spite in his voice. "Now, if you'd be so kind as to hand the ancient sceptre that you took from me."
Eggman didn't wait long for an answer. His robots pointed their guns at them, and fired. They both jumped High in the air to dodge, with Rouge taking flight. Eggman quickly moved on her, punched her hard with one robotic arm, and knocking her down. Rouge released her grasp of the sceptre, and it fell to the ground along with her. Shadow acted quickly, and caught Rouge before she hit the ground. "Nooooo!" Eggman yelled in protest as he could only watch. The sceptre was out of his reach, and he couldn't get to it fast enough as it fell. Worse, none of his robots had hands to catch it with. He could only watch as it hit the ground, and shattered to pieces.
Electricity crackled from the robots as they suddenly short circuited. Everything was quiet at first, as Shadow dropped Rouge on her feet, and approached the destroyed relic. Suddenly, the energy released from the sceptre's remains, rising to the sky as a pillar of blue and black energy. "It's no use! Fall back, fall back!" Eggman shouted in a panic before he flew away. 
Shadow and Rouge watched as the energy swirled around them, destroying the robots, rose up, and finally landed n Shadow's shadow. It stretched out before her, and a shape rose from it, surrounded by an aura of black and blue. It quickly took form. and broke away from her shade. In mere seconds, Shadow was staring at a near mirror image of herself. The imposter had a couple of differences. She the streaks on her fur were grey, instead of red, and she had green eyes with sinister, slitted pupils. "Ahahahahahahahaha!" the doppleganger cackled as she stumbled slowly toward Shadow. "Fate can be so ironic. I never imagined i would be resurrected by your Shade. I thank you, Shadow the hedgehog." She mocked as she bowed before her. 
"Who are you, and how do you know my name?" Shadow demanded. The imposter hedgehog continued to to stumble toward her. 
"You don't remember me? I am Mephiles the dark."
"Have we met?"
"Oh we have, and I owe much to you, Shadow." she held out her hand as soon as she was close enough. "What you gave to me, I now return to you." the imposter said before an orb of vibrant energy formed above her palm. "Oblivion!" she shouted, as it quickly enlarged and absorbed all three of them, before it disappeared, taking them with it.
"Hmm, that's odd." Eggman said, scratching his head as he observed he screen on hovercraft while he flew back toward his base. "The energy from the scepter just...disappeared, along with Rouge and Shadow." he thought to himself. Suddenly the console beeped rapidly. "What? the scepter's energy again?!" he shouted in surprise before Mephiles appeared before him in a flash of light. 
"Hello doctor." she greeted calmly. "what? Shadow? is that you?" Eggman asked, confused at the similarities and differences from Shadow's imposter. Mephiles suddenly transformed before his eyes. The scleras around her slitted, green eyes turned red, and a crystalline exterior formed all over her body.  "No doctor, I understand your mistake though. I am Mephiles, the dark. The scepter you had was my prison for many years, until you freed me. To show my gratitude, I would like to help you conquer the world, if you will let me." Mephiles explained. "What if I told you that there was an ancient power, great enough to end the world, that you could take control of?" 
Eggman raised an eyebrow, clearly interested. "I'm listening." he responded.
Mephiles floated close to him. "Allow me to tell you about the flames of disaster, and its connection...to Soleanna."
From a forest, Mephiles, in her lesser form, looked on at the city of Soleanna in the far distance just as the sun finished setting. She watched as Eggman and his robotic minions flew through the air toward the city. The dark entity chuckled to herself in self satisfaction. "Everything is set into motion." she thought to herself,  "Now all I have to do is wait." Mephiles' eyes widened in surprise when she suddenly felt hands grab her breasts from behind.
"Guess who?" Sonic teased playfully as he brought his face into view from the side as he stood behind her, "fancy meeting you here, Shadow." Mephiles was surprised to run into Sonic so soon. 
"Ugh! L-let go of me!"
"Babe, when has that ever worked?"
Sonic chuckled as he pressed her against a nearby tree. She gasped loudly when he gave her ass a firm slap. "So what's with the grey streaks? did you get so broody that the red's too much color for you now?" the blue hero joked as he quickly undressed her. Mephiles tried summon her power at first, but stopped. She couldn't try to kill him yet, it was too soon in her plan. Thankfully, being mistaken for Shadow kept everything intact. Unfortunately, it also meant she had to play along for everything to go smoothly.
She felt Sonic guide her hand by the wrist until her palm touched something that felt hard, warm, and very big. Mephiles looked down slightly, and her eyes widened in shock at the sight of Sonic's erect cock. It was impossibely huge, with a matching pair of big balls that swung heavily underneath. "W-W-Where d-did you hide that...that...thing?!" she stammered in disbelief. "Haha, you don't need to flatter me, Shads. Now, ready for your favorite beef ?" he asked as he gripped her head, and shoved her face into his crotch. Sonic's shaft was so hard, that Mephiles bumped her head on contact with it. She was quickly surprised by how hot it felt as it brushed against the side of her face and the stench of it aroused her. "Come on, babe. Let's do a little quickie before I check out the festival."
With Eggman about to attack the festival, Mephiles needed to get this over with as quickly as possible. As much as she hated it, she had to comply. Fortunately, Sonic couldn't see her mouthless face. The lower half of it twisted until it split open to create a mouth. It was the first time Mephiles ever made one. It opened wide to a freakish size in a monstrous, jack-o-lantern-like shape. She quickly swallowed Sonic's cock whole, eager to get it over with.
"Woo! Someone's hungry today!" he exclaimed in approval. The blue hero leaned his head back with one hand on her head as she sucked him off. It didn't take long for her to start a rythm and pick up the pace. She was amazed at his thick girth. She could feel the heat of it as it went down her throat. As she dragged her tongue across its surface, she could feel the veins pulse against it, but most of all, the taste of it was intoxicating. Mephiles blushed heavily when she realized that she was enjoying it. She liked taste and feeling of his huge, hot meat in her mouth, and it filled her with shame. Shame, and self-loathing, and it turned her on.
"Ah god, oh hell yeah! Getting close. Gonna blow it!" Surely enough, his cock swelled up before Mephiles felt the first hot rope of seed strike the roof of her mouth. Without thinking, she gulped it down. Her eyes widened in surprise at the heat and thickness of his cum as she felt it travel down her throat. What was more surprising was the volume. Sonic pumped more and more seed almost without end. Despite her effort, plenty of it escaped her mouth and dripped to the ground. Mephiles pulled back and quickly turned away. She leaned on a tree with a hand on her mouth as she choked on his excessive seed. She suddenly felt Sonic press her against the tree from behind. 
"Wh-what are you doing, aren't you done?!" Sonic chuckled at her bewildered question. "Babe, we're barely half-finished." he replied before he stuffed his whole girth into her pussy from behind in one hard shove. Mephiles cried out in shock when she felt his fat cock push all the way inside her, spreading apart her inner walls. "Ah yeah, warm, wet, and soft, just the way I like it." The blue hedgehog complimented before he began to thrust into her. He pounded her so hard, that the branches above shook and rained down leaves. Mephiles' eyes rolled back into her head as her mind went blank from the overwhelming pleasure. She had lost all mobility, and could only lay against the tree and moan loudly in ecstasy as he completely had his way with her. Even though he just climaxed, his dick hadn't softened one bit. In fact, it felt even more hard than before. Mephiles never expected for a close encounter with Sonic to be like this. She had never felt such ecstasy and lust. It made her feel ashamed, humiliated, angry, and it aroused her even more. 
As time went on, the pleasure rose more and more as she got closer to her peak. "Gonna blow it! Take it all!" Sonic exclaimed with an excited grunt. Surely enough, she could feel his massive cock stretch out her pussy as it swelled inside of her. She screamed in a mind-numbing orgasm as soon as she felt to the first shot of warm cum hit her womb. Her inner walls clenched down, trying to capture as much of his virlile cum as possible. Despite his orgasm from before, Sonic had just as much seed to give. The volume of it swelled her belly and dripped down to add to the mess on the ground. After what felt like forever, Sonic's blasts of semen finally died down, and his cock finally went flaccid. He pulled out, released his hold on Mephiles, and she immediately collapsed face -down on the ground. Sonic let out a sigh of relief.
"Woo! Good to get some sweet release after being pent up for a bit. Was it good for you too, babe?" Mephiles could only groan in response. Suddenly, there was the sound of explosions in the distance. Sonic turned to see smoke rising from Soleanna. "Uh-oh, looks like the festival's in trouble. I'll bet it's Eggman, again." Sonic turned back to Mephiles. "No need to worry, sexy. Just ride the afterglow and let me save the day. I'll catch you later." he joked before he quickly raced off to the festival.
Mephiles laid on the ground an exhausted heap. She panted as her thoughts returned to her. She didn't expect to be so completely defeated by sheer sexual dominance. Trying to kill Sonic up close was now completely out of the question. The plan suddenly became more complicated. "I need help with this." she realized.