Turtles Forever2009

Raphael:
You plan on doing us in, there's gotta be an easier way!

The Shredder:
Oh, you shall perish, but not yet. You see, like you, I recently learned that ours is but a single dimension in a multiverse of dimensions. Intrigued, I used this very portal to survey them all. Which is when I made a startling, horrible discovery. There are not simple eight of you, but SCORES OF YOU! Behold, a multiverse of accursed Teenage Mutant Ninja Turtles!

[the Portal displays large images of multiple Turtle dimensions]

1988 Leonardo, 1988 Michelangelo, 1988 Donatello, 1988 Raphael:
AWESOME!

The Shredder:
Destroying the eight of you would accomplish nothing! So long as ninja turtles exist somewhere in the multiverse, they will interfere in the plans of The Shredder. Our epic battle is never going to end unless I put an end to turtles... FOREVER!

Splinter:
Even a creature as power-mad as you, cannot believe he has the ability to subvert the entire multiverse!

The Shredder:
Let us put that to a test, vermin! It seems like branches hanging off a single tree, each of these dimensions sprang from a common source. Destroy the source, and you would set off a chain reaction that would destroy ninja turtles everywhere, forever more! And so, you are being scanned. Broken down, for the sole purpose of discovering your "source" DNA. Two turtle teams from two turtle worlds. Different in so many ways, but deep down there are similarities. And those similarities will point the path to the source dimension: Turtle Prime!