The Turtles, Shredder and Krang's battles skills, powers, and memories are absorbed into Dregg, and he becomes a super-being. He detains his drained prisoners and prepares to initiate the final stage of his plan to conquer earth by using the matter transporters to project pieces of the very sun itself onto any city of his choosing, he will continue to do so until Earth conveys onto him the title of emperor.
Splinter, meanwhile, is visited by time-travelers from the distant future, which has come to aid the TMNT, at the approval of Splinter, they travel back two years, and pluck a team of turtles from the past. But there is a price to pay for this deed, the past Turtles only have 24 hours before they must be sent back, or the turtle's present time line will cease to exist.
The past TMNT, together with Carter arrive on board the Dreggnaught, and after a fierce battle with Dregg's underlings, are able to rescue the present-day TMNT, but their skills and experience are still retained...