Remember that time April transformed into a demon?

[Original TMNT Cartoon Fan]

Originally Posted by neatoman

"The [original 'Teenage Mutant Ninja Turtles'] five part miniseries ends with the Turtles having to battle an alien armada that is coming through a gigantic black hole dimensional portal being projected in the sky directly above New York City. This dimensional portal projector has created a giant opening in the sky, with a whole alien armada coming through it. That's what the turtles are facing. The way to stop it is to shut down the machine that's generating the portal. All I have to say is: you're welcome Joss Whedon!".

Reminds of the season 3 ending.