This is the part where Megatrain rises out form his prison in Thomas' Place as a Prime.
[then suddenly, the grounds starts to rumble as "The Propechy (from The Lord of the Rings: The Fellowship of the Ring)" plays]
Tirek: What the?
Ernie: Huh?! [his pupils shrink and his mouth drops wide open]
Elsa: [falls to the ground] Oof! What's going on?!
[then four beams start shooting out of the ground]
Ed: LOOK AT THAT!
Spongebob: Am I seeing things or is there something that's gonna come out of the ground?
[then beams open up a portal]
Princess Celstia: What the...?
[Then a giant robot starts rising]
[all of Stuingtion's Engines look]
Hugs: Could it be?
Mucker: Is that?
???: [thunderously cackling]
[everyone watches in complete shock as the mysterious robot rises out of the ground]
[the figure completely rises out of the ground revealing to be Megatrain!]
Percy: BUST MY BUFFERS!!
Henry: BUBBLING BOILERS!!
Emily: TREMBLING TRACKS!!
Fix-it Felix: [his jaw drops]
Wreck-it Ralph: NO WAY!!
Rainbow: Oh no!
Fluttershy: Oh my!
Pinkie: Oh no, no, no, no, no! Not good, not good, not good, not good!
Brian: Oh, my God!
Edd: Good lord!
Spongebob: Is that!?
Patrick: It must be!
Eugene Krabs: Me, dear god!
Sandy: Holy Gracomoly!
Ernie: What in the hell?
Steamy: Oh no.
Shai-Shay: It's him!!
Mako: IT'S MEGATRAIN!!!
Princess Celestia: WHO ARE YOU?!
Megatrain: [looks to our heroes] I'm Megatrain! The most powerful Deceptitrain in all the world! And did not build my machine to have a centaur, to take my army away from me!! Now that I'm free, I can gain my amry once again! [walks up to Tirek] Hello Tireky, long time no see. Thanks to you I am now back! I should thank you, but it'd be more appropreite to do this.