Ok so this idea I've had for a while (this is basically what I would do but I'm going to put it down as y/n so people could perhaps take this idea and run with it) it was inspired by all the self aware yan Turtles so the turtles kidnap y/n from our world she manages to memorize/or take a picture of the blueprints of what Donnie used to bring her there now I'm not sure when they build the handheld device to literally go back to their dimension Donnie has too many cameras so trying to do it in the layer would be kind of difficult though she is interested in learning robotics which I doubt Donnie would say no too anywho so they managed to make a handheld thing to get them back to their own dimension whether it was before or after they escaped that is something I'm not quite capable to figure out if it would be possible to hide something like that from any of them unless you disguise it is doing something else so they managed to escape and do the portal thing but the portal is unfortunately unstable she's running out of time though and needs to go now portal explodes well she's somewhere through and splits her in half one going back to our world like they were never kidnapped in the first place an her stuck with the yan turtles actually not as injured as you would think because most of the energy from the interdimensional portal was absorbed into her body she hides what's left of the device and injured tries to get away from the turtles (I thought I would put this there she doesn't know but finds out later if she was split in half) she eventually collapses from the injuries and is caught Donnie finds that she absorbed interdimensional energy and also a split in half which they're all aesthetic about since now she doesn't have to worry about her family or anything missing her Donnie also finds that the inner dimensional energies she absorbed kept her alive at the time is now slowly killing her as it is destroying her DNA so besides to try and turn the energy from what it is to Napa which works but speeds up the process in which the DNA is degrading so he Frankenstein some DNA together basically and it seems to stable her out. Ok so serious two options to how she escapes from them the second time A manages to escape them while human and ends up getting mutated later on in another world with the turtles that aren't yandaries or B they go to mutate her for many reasons one being to make sure she stays stable and in the confrontation of it all while being mutated she manages to get to another dimension with the turtles that aren't yandere's there is also two options as well of which timeline she will go in both having their own ways to change the story in I also wanted to add in that she hits her head so she doesn't remember everything as clearly (what I mean by not remembering as clearly is think of it like videos that have been corrupted you can still watch them sometimes but they're grained and missing parts or scratch CD)
Ok so I think this is the longest thing I've ever written and it's not even all of my idea @yanteetle I did what you said write down my ideas and hope I can perhaps write an actual coherent story someday or just put it out there for other people