A/N: I wrote a story on a forum before but never thought to upload it. The basis of it came from an RP I had with a friend of mine, in which my own OC was born from it. Then I got the idea what would happen if he were to end up in Sonic's world, and given his extensive background, it would make for some interesting plot. Originally, I planned to make a prequel to this story, but turns out I ain't ready to make a TF2/Sonic crossover, and I don't think I'd enjoy writing it. So, this story is the very first for a line of others to follow, and maybe some 'what if' stories thrown in.

Disclaimer: All characters belong to Sega except my own OC. Also Gray Mann and some weapon references belong to Valve as there's breif mention of them.

-Back Story-

Some months ago, Mobius actually saw a hint of peace. Eggman had been thwarted once more, or should I say his so-called 'son' A.D.A.M. Of course, the doctor never had an actual blood-related offspring, but he considered his newly developed A.I. as one. Built specifically to keep his systems under key, Adam was everything the doctor could hope for: strong, reliable, and unrelenting in flushing out any intruders to its creator's networks. He was easily a match for the Freedom Fighter's own advanced A.I. Nicole. But as it would turn out, loyalty was not one of Adam's strong points.

Like Nicole, this A.I. had a simple thought process (obeying all of Eggman's orders) until it grew sentient enough to express feelings and later develop its own motives. Naturally, the doctor saw this as a problem (given what happened with E-102 Gamma) and decided to erase Adam from existence, but not before the A.I. could download its programming into microscopic robots known as nanites. It later used said nanites to infect and control a local known as Tommy Turtle. No one knew of Adam's true intentions, until it used both Shadow and Tails' super forms to rein in every chaos emerald in the universe. Contrary to popular belief, there weren't just 7 emeralds of a different color. There were literally thousands of these emeralds.

However, before Adam had a chance to use them, Sonic used his super form to put a stop to it while Tails and Shadow, deciding that the emeralds were too powerful for anyone to get their hands on, decided to seal them in a pocket dimension for safe keeping. No one would seeing them for months after this. As for Adam himself, well...let's just say Tommy took him to his grave.

Anyway, that's how the usual story goes, but here's where the story becomes a bit interesting. A few months after the whole 'Adam' fiasco, Eggman came in contact with someone from, surprisingly, a different dimension. Now, it wasn't from Blaze's world or some other Sonic-related universe, this one was entirely different. The man he spoke with introduced himself as Gray Mann, a billionaire from his world who had been using a strange substance known as Australium to power a life-extending machine attached to his spine. Like Eggman, Gray also had an army of robots at his disposal. Whether Gray was a billionaire now is under heavy debate, especially since his robots are literally fueled by money of all things.

The meeting itself was really an accident. Gray was using his engineer robots to find somewhere to escape to as a group of mercenaries were closing in on him. Normally he wouldn't be too concerned, but months of fighting severely depleted his manpower and resources. Due to an, at the time, unknown space anomaly occurring, one of the modified teleporters reached out to Mobius. After sending a few robots to do some recon, Gray realized this was an entirely different world, and possibly his chance to cheat death. Gray wasted no time in establishing himself a base, (along with killing anyone who came near). The Freedom Fighters originally thought it was Eggman, but soon discovered it was someone else entirely.

Gray's own army proved to be a threat on its own, but when he decided to join forces with Eggman, the two became almost unstoppable. With the absence of the emeralds, many of their attempts ended unsuccessfully and the two mad men seemed on the edge of retaking Mobotropolis. Even Sonic was abit impressed that old Eggy stepped up his game. However, the situation wasn't entirely hopeless. Thanks to Rotor, Tails, and Nicole, they found out where Gray had originated from and decided to get help from people who knew him better and could hopefully turn the tide in this war. It was here, that the Freedom Fighters met the mercenaries of Builders League United and Reliable Excavation and Demolition. Naturally, all of the mercenaries were shell-shocked at seeing talking animals (Tavish even thought there was something in his scrumpy). They also weren't exactly willing to believe Gray had escaped to another planet and had simply fell off the grid.

However, there was one person willing to listen to them on the spot, RED team's engineer Kor T. Royce. Kor was a male of Caucasian decent and haled from what many assumed was the southern US due to his accent. Normally most engineers were in there 30s or 40s, yet Kor was still in his 20s, putting him not that much older than the Scouts and while he didn't have 11 PhDs as the other turret masters liked to boast about, he did have 2 in robotics and weapon systems. He was known as an innovator of sorts for the mercs. While he used the regular Mann Co. licensed sentries all engineers typically worked with, Kor decided to build something deadlier, which included flame-throwing turrets, rocket howitzers, and as a personal test on accuracy, sentries that could actually snipe their targets. Such devices proved crucial in some battles. He also had many other ideas that sounded awesome, but too impractical to be of any use.

After some debate the mercs decided to take the Freedom Fighter's advice and follow them. Unfortunately, the star posts used to access their world would only remain open for so long, so Kor had the mobians take a teleporter exit to the other side before it closed. Now, using a regular teleporter seemed fine when moving from one location to another, but if that location meant another universe, there was no telling what would happen during the transfer phase. As such, Kor was the first to use it. All seemed normal, but right before he was teleported the device shuttered and flickered as it tried registering the human to a different plane of existence. What happened next changed his life forever.

Kor made it to the other side just fine, except he wasn't a human anymore. Kor found himself turned into a mobian North American Red Fox, much to his horror. After freaking out for 7 minutes, and getting a good slap from Sally to knock a little sense into him, the human-turned-fox clamed down and looked over the teleporter for what went wrong. Turns out the main adaptor had adjusted itself upon someone stepping on it (they always do this when being put to use), but due to the huge difference in location it forced itself to adapt the user to its environment. Kor decided to fix this so no one else would end up like him, though the thought seemed funny for a moment. (A/N: Pigeon Medic and Pootis Bird Heavy anyone?) Embarrassingly, Kor had to find new clothing as being turned into an animal decreased his overall size.

Once this was fixed, everyone else was brought over along with their equipment. Antoine questioned whether it was a good idea enlisting the help of 18 heavily armed men, but as Sally noted, they didn't have much of a choice. In the battles that followed however, Antoine would become thankful they did bring the mercs in. It was very clear that each of the mercenaries fighting styles were odd or simply unbelievable, such as Soldiers rocket jumping, pyro's insane airblast, and occasionally Demo's penchant for decapitation, yet the heroes were glad they weren't on the receiving end of it. One of the biggest game changers was the Medic's combination of different ubercharges. Being invulnerable while spamming criticals everywhere? Fuck yes. It should come as no surprise that the mobians were shocked several times by the mercenaries' common display of reveling in destroying the robots, especially after a long kill streak.

Gray wasn't too worried about the mercenaries when they first showed up, as he believed his forces and Eggman's were more than enough to handle them. But in the weeks that followed he found the heroes were getting closer and closer to their base. He grew more and more desperate, to the point he turned on his own collegue and tried to run the show himself. It felt as if nothing could stop the heroes from end this threat once and for all. In a final decisive battle, hoped to keep just about everyone distracted while he would slip away, yet he didn't count on someone being thorough in wanting to put his ass in a grave.

Eggman slipped in the shadows and wasn't heard from after that. Sonic and the others knew that he was still out there, but they weren't too concerned about him. The doctor knows he lost and wouldn't think twice about wanting to take on Sonic, the Freedom Fighters, and several armed men at once. In the days that followed, the mercenaries of TF Industries returned to their own world, except for two. Klaus, RED's medic, was so interested in Mobius he decided to stick around to learn more about the anthropomorphic animals, though given his eccentrics, everyone was justified in being a little creeped out.

For Kor, the situation was even more obvious...

-Present Day-

It's been about a week since Gray Mann was finally killed. At times it felt as if the whole robot war he started would never end, but now they finally got him, well technically Kor killed him. The man had deserved everything that came to him: attempting to kill the former engineer and his fellow mercenaries whom he called family, threatening and killing thousands of innocents, he ended up causing Kor to lose one of his hands, and to top it all off, Gray betrayed Eggman just to spite everyone. Kor still smiles at the memory of ripping the basterd's Australium-powered life support system from his back.

Currently, the engineer was laying on the bed of his new home, staring at the robotic hand he made as a replacement. It was a standard issue Gunslinger licensed by Mann. Co., which allowed the user to build mini sentries. It was important that all engineers knew how to build one of their own in case they needed to replace a hand. Kor chuckled to himself as he remembered the tons of weapons Mann Co. gave to both RED and BLU to test, or in other words, kill each other with. They may not be mercenaries anymore, but he was still an engineer at heart.

Although Kor wished to be back on familiar grounds, he knew he couldn't live in his home world even if he wanted to. Apparently that whole 'turning from human to mobian' issue was permanent.

"Well, at least this world is full of adventure, with Sonic being around and Eggman still schemin." Kor mused to himself. "Plus, given the tons of tech this world has, I might be able to make more than just sentries." He smiled deviously at the thought.

Being able to make robots of destruction was still in his blood, despite having mellowed out of his destructive tendencies to a degree. He then decided to stroll over to Freedom HQ to see what everyone else was up to.

Since Kor decided to live the rest of his life on Mobius, and with some suggestion from Sonic and others, he was staying in Knothole where the Kingdom of Acorn had resided. To him, he supposed it made sense given that Sally was a princess and all, plus he didn't know anywhere else to go. Within a few days he had the chance to meet the trio of the main trio of the Chaotix, including their other members like Julie-Su, Mighty, Ray, Saffron, and even members of the royal family like Sally's brother Elias. They were a very nice bunch in his mind.

-Freedom HQ-

"You think he'll be estatic about what we'll tell him?" Tails questioned.

"Probably, but he doesn't talk as much as he used to. Almost reminds me of Shadow." Sonic said.

"He might be just thinking about some issues of his on Sugah Hog. 'Sides, movin' into new digs ain't exactly exciting to some." Bunnie said, though she wondered how he lost his hand since no one said anything about it, not even the other REDs or BLUs.

"Being zat he used to be a crazed merc fighting all ze time, I'm sure he's just getting used to ze peace." Antoine says in his distinct French accent.

"Regardless of that, I'm sure Kor will be happy to be a part of the Freedom Fighters. He even told me himself he thought it would be a fun adventure here." Sally points out.

Sonic chuckles. "I wonder what his definition of 'fun' is."

"Something I may not want to know, however I am amazed at the kind of weapons he made in his own time." Rotor mused. Kor dropped hints of a few other turrets he used back in the day besides his standard sentry, but didn't give much detail about it.

Then they hear chuckling from the stairs. "I'd be happy to tell you more about it Rotor. So what are you all doing down here?" Kor asks as he entered the base. He notices none of the Chaotix are around. "Annnnnd where are Knuckles and the Chaotix?"

"They're acting as body guards for Mina while she's on her world tour. Anyway come on down Kor, we need to speak with ya on something." Sonic says, laying his feet on the table.

"Um, ok." Kor takes a seat in a beanbag chair opposite of the others. "So what's up?"

"Well, we've been discussing this and, thanks to your invaluable efforts in stopping Gray Mann, we would like to appoint you as a member of the Freedom Fighters!" Sally exclaims.

Kor raises an eyebrow at this. "Really?"

"Of course. You might be a little nuts at times," Kor chuckles at that, "but we all think you'd be a valued team mate that can help topple Eggman." Tails comments with a smile.

"Plus, if you can handle them Gray bots, Eggman's drones won't be an issue for ya." Bunnie says with a tip of the hat.

Kor smiles at this. He had a feeling they would let him join, but he was unsure about this given the fact he can become a crazed gunman from time to time. Sonic, Tails, and Sally once saw him gun down 50 robots with his sentry gun, all while he was laughing like a crazed maniac.

"Well, y'all got yerselves a new teammate then, pardners. I'm sure this is gonna be a heck of a lot fun beating Egghead." The others chuckle in agreement.

Bunnie then grows curious as she stares at his hand. "Not to sound rude, but how did you lose yer hand?"

Kor rubs the back of his head of his flesh hand. "Well, that's abit of a story really. Oh and I can tell ya about some of my machine Rotor." Rotor smiles and pulls up a chair.

A/N: And that's all she wrote, for now. Went back through this chapter recently and edited some stuff out. Realized I should've fleshed out the first chapter a bit more. Anyway please review.

Edit: Re-written a second time. This is my main first story. There won't be a prequel for this, so I edited it to be as such.