A parallel to modern day Earth filled with secrets and hidden plots involving alien invaders, mutants, ninjas and other threats to an ignorant populace.
Type: BlossomTMNT-1 is going to be starting on the World Tree just after the events of the Season 3 mid-season finale "The Battle for New York" (parts 1 and 2) which can be read about here: https://tinyurl.com/Battle4NYC1
TMNT-1 is a binary dimension. In addition to the primary dimension in which Earth and "normal" space can be found there is a second dimension that makes up this world: Dimension X.
Home to the Kraang, Dimension X is inimical to terrestrial life - toxic air and caustic "water" being but a few of its threats. These can be avoided with the right equipment or adaptations but this generally pink-hued world is unpleasant to say the least.
The Utrom are a small, tentacled species that vaguely resemble brains and are native to Dimension X. They were peaceful and had a focus on science - studying their dimension and the one it closely neighbored (in which Earth is found) - until one of their leading scientists (an Utrom known as Kraang) found a way to harness a substance now called mutagen from worms native to their dimension. Using this substance Kraang transformed himself into a giant with psychic powers; using these powers he enslaved most of his species which he redubbed the Kraang after himself and took to calling himself Kraang Prime.
In addition to the ever-present mutagen, the Kraang are a source of advanced technology on Earth: energy weapons of all sorts, "krangdroids" (robots that an Utrom can control from an abdominal cavity), trans-dimensional portals (see below), and more.
The Kraang use trans-dimensional portals to travel between worlds. Prior to their world becoming a blossom on the World Tree they could use them to move freely between various dimensions. Since this joining, the only reliable portal use since the joining is between Dimension X and the "prime" TMNT-1 dimension although the portals can still be used to travel to other worlds by hijacking vines to other parts of the Tree; this hijacking is, however, unreliable and is a source of study for the Kraang and others - including Donatello of the Teenage Mutant Ninja Turtles.
In this world, the term "mutant" is most often used to describe beings affected by the glowing, neon-green, mucilaginous ooze from Dimension X called mutagen rather than naturally occurring mutations, as it is more commonly used throughout the majority of the World Tree. For world natives, exposure leads to mutation which can range from animals taking on human traits (such as the Ninja Turtles themselves, Raphael's former pet turtle Slash, or Pigeon Pete) to humans taking on animal traits (such as Master Splinter, Bebop, or Rocksteady), to either taking on the traits of other objects (such as Muckman) or simply growing in size and/or gaining exceptional powers. In general, whatever is being mutated takes on traits of the last living thing that it had touched. Additionally, native Kraang-hybrids (like April O'Neil) are immune to the effects of mutagen.
Outsiders, beings from other dimensions, have a strange relationship with mutagen. They are unpredictably affected by the substance. Some are completely immune, others are affected but shed the changes on departure and also randomly either regain them when they return or not, while others can be affected by it permanently just like natives; there seems to be no rhyme or reason to this and even individuals from the same world can sometimes be affected differently. (OOC: it's up to the individual players to decide how it affects them if they are not from TMNT-1. Also, these sorts of things require approval from staff as TPs or Upgrades depending on how long they will last and their permanency.)
While scholars from other worlds are likely to have fits about this, the ninja of this world match what is deemed to be a fabrication of entertainment in most others. They wear uniform costumes, form clans and continue to this day as secret societies far beyond their native Japan. One such clan, dating back to feudal Japan, is called the Foot and has branches throughout the world including New York City itself.
Ninjutsu itself, the art of the ninja, is a combination of a martial art fighting style, espionage techniques and a tradition of unconventional approaches to strategy and guerrilla warfare. More details can be found in many places on the Internet including here: https://tinyurl.com/ninjutsu-link
Magic is real in this world. Whether practiced by Foot Mystics, Time Lords and Ladies (who are not aliens with two hearts!) or others. It requires some combination of power, ritual, and training to produce almost any imaginable effect.
While TMNT-1's canonical focus (up to the cutoff) has been on Earth (specifically New York City and North Hampton, a town and rural area in Upstate New York within this world), the galaxy at large is populated by a multitude of species of sapient species - including human-like species and humanoid saurians that resemble, and are genetically similar to, terrestrial Triceratops from the late Cretaceous called Triceratons.
TMNT-1 has only recently integrated into the World Tree. In Dimension X, the Kraang are fully aware of this and have begun actively studying the changes in trans-dimensional physics resulting from the changes wrought by the paired worlds becoming part of the greater tree. Conversely, in the primary dimension, while there are pockets of informed individuals scattered across the greater galaxy most sapient beings run the gamut from complete and utter ignorance of the World Tree and other dimensions to being only vaguely informed and either curious or fearful of the rumors they are hearing.
On Earth, most people are clueless despite the random connections that are already occurring. The Foot, though the help of their Kraang allies, are aware of the new worlds and have begun sending out feelers to attempt to establish connections to similarly minded organizations across the expansive multiverse. Fringe (for the moment) elements of the FBI and ICE in the United States, similar groups in other countries and even the UN have fragments of the truth and could end up crystallizing into a multi-national policing agency over time. Non-human inter-dimensional travelers are most likely to be mistaken for aliens or -- by those in the know of the Kraang history -- mutants if not thought to be people in costumes.
Additionally, the Utrom are already debating reaching out to the governments of Earth. Should a large-scale attempt to police the vines of the World Tree begin they would likely reach out to provide assistance.