TMNT: The Game

Alternate Universe notes:
Karai is Shredder's biological daughter.
The reason for the foot and Lotus Clans' clashes against each other is different and will be revealed throughout the story.
Shredder is more resembling the one from the 1990s cartoon in looks, meaning no burn scars on his face. But he is extremely more competent than that one.

Now for the Summary:

It's not a dream. It's survival.

Michelangelo Hamato and Oroku Saki aren't too concerned about the strange dreams they're having- ones where they work with an 'imaginary' version of the other to defeat monsters or solve problems- at first.

The duo are chosen to play a game by someone- or something- only known to them as Game Master. They wake up at the beginning of each level- each a new location with its own objective, atmosphere, and story. And each level is more intense or dangerous than the last. But something they all have in common: Waking world consequences.

They learn pretty quickly that they need to work with the imaginary version of the other in order to pass and survive their trials. But as things become harder to explain in the waking world, Saki and Mikey must consider the possibility of these dreams not being just dreams.

As they progress in this... game... working together becomes ingrained to the point that even in the waking world, they fall into the rhythm of working together. With the partnership in both worlds forming, neither side is quite sure how to handle the drastic changes in them.

But what if these changes aren't really drastic, just no longer hidden? How do the two opposing sides handle the situation? And how are Saki and Mikey going to survive when they have worries in both realms? It's sadism and survival as they try to figure out what exactly they're up against.