The setting

The day that Dimension X was sealed away permanently, was the day that everything completely changed.  Donatello’s plan had worked flawlessly, the implosion of the Portal Device had effectively pulled the Technodrone, Krang and the Shredder back to Dimension X as well as finally sealing the inter-dimensional barrier for good, but then the incident happened.  As everything in the immediate vicinity was pulled into the temporal implosion, the Turtles has managed to bind themselves to steady mounts to keep from getting pulled in along with everything not tied down.  Three of four bindings held strong, Raphael’s though was pulled loose as he was trapped in the inter-dimensional vortex with little hope of breaking free, Michelangelo being the closest to the portal point reached out, grasping Raphael’s hand swearing that he would hold strong, Raphael on the other hand knew it was too late, no amount of strength could pull him free and the portal was fast closing, the swirling clouds of Dimension X were surrounding the turtle as he yelled for his brother to let go, but Michelangelo refused, even as the portal was shrinking he held on until the portal finally sealed severing his left arm mid bicep.  The pain of the dismemberment failed in comparison to the fact he had been unable to save his brother, he soon collapsed into unconsciousness.

That was 5 years ago…

Eventually the Turtles accepted the loss, but held onto the hope that one day they would be able to find Raphael by some means, though the loss affected each brother in their own way.  Michelangelo decided that he would continue the good fight, adapting to his handicap despite the fact that Donatello repeatedly told him he could fabricate a false arm.  Michelangelo refused, only using a crude prosthetic in rare cases (such as when lifting weights, primarily to act as a balance).  His attitude became grim for a short while before being called back to his senses, by Mondo Gecko, eventually reverting to his old self, just slightly more mature.

Donatello buried himself in his lab work, often trying to find any way to possibly reopen the collapsed dimensional barrier, while also maintaining new and various equipment for their fight on crime.  Rarely leaving his lab for foot work, except in rare instances, he often maintained a presence alongside Michelangelo via the Metalhead robot, which he often controlled remotely, despite its ability to be self efficient.

Leonardo began to question himself repeatedly, chalking the loss up as his fault because he wasn’t as good a leader as he should have been.  This led him to disappearing months on end in hopes to improve and atone for his perceived failure.  It became far easier to assume that Leonardo would not be around than to hope that he would be.

With the loss of Raphael and the flightiness of Leonardo, the Turtles had come to depend on various allies aid in patrols and battles.  Mona Lisa, a mutated physics student  who had once aided Raphael against a pirate called Captain Filch, had made her way to New York, joining the Turtles in their new home, an abandoned hotel created by the mutant A.J. Howard in a crazed attempt to lead mutants and enslave humans, now decked out with all kinds of technological improvements.  Mondo Gecko, a young Gecko that mutated in the same ooze as the Turtles also was a regular ally being the one that verbally lambasted Michelangelo to quit trying to think like others and to think as himself, was another regular member of the team.  Other allies frequented the team as well, including the non-mutants the vigilante Casey Jones, his wannabe vigilante daughter Shadow Jones, a young teen

named Zach who often claimed to be the 5^th Ninja Turtle, and the freelance reporter April O’Neil, among others.

Donatello had also established a contact network with allies all over the country as a means of providing aid whenever needed.  The “Punk Frogs” in the Florida Everglades, the team of Mutants known as the Mutanimals out west (including enemy turned ally Leatherhead), and a select few other Mutants spread out over the United States, being hot linked to the Turtle Team in New York.

Master Splinter remained in the lair as an advisor and still trained both Michelangelo and Donatello though in recent years he has focused more on the inexperienced fighters, such as Mona Lisa, and helping them learn to stand toe to toe with his “Turtles

Of course with the loss of the Shredder, many other more enemies had began showing up throughout the country, many vying to fill the hole in power that was left behind.  A man named Hun had began to bring various gangs under one banner, creating a gang known as the Purple Dragons with  a vested interest in technological and extraterrestrial advances throughout the city, also bringing his own gang of Mutants into the fray led by Bebop and Rocksteady.  A woman claiming to be the daughter of the Shredder had managed to lay the groundwork for a new Foot Clan in the city, though her numbers were small they grew daily in both human and robot warriors (many of which were developed after Baxter Stockman’s brother, Barney Stockman began to tweak the designs).  The man known as the Rat King had come to a rough alliance with the Turtles, assuring them that he would stay out of their way, provided they remain out of his as he maintained a small society deep within the bowels of the city, complete with his loyal rat subjects as well as several humans who had fled the city for various reasons.