When Worlds Collide, Part 1

When Worlds Collide Part 1 is a one-hour episode of 2012 animated TV series airing June 18, 2017.

Synopsis
The Newtralizer returns to New York more powerful than ever before and joins forces with a dangerous, unexpected ally; with the help of Mona Lisa, the turtles fight back to defend their city.

Major Characters

 * (Mae Whitman)
 * (Nolan North)
 * (Rob Paulsen)
 * Karai (Kelly Hu)
 * G'Throkka/Sal Commander (Keith David)
 * (Seth Green)
 * (Greg Cipes)
 * Mona Lisa (Zelda Williams)
 * (Danny Trejo)
 * (Sean Astin)

Minor Characters

 * R’Kavaka (Nolan North)
 * (Peter Stormare)
 * Earth Protection Force
 * Utrom Council
 * Miss Campbell/Queen (Cassandra Peterson)
 * Pawn (Nolan North)
 * Irma/Rook (Kate Micucci)
 * Utroms (Nolan North
 * Space Heroes: The Next Generation
 * Captain Ryan (Brian Bloom)
 * Crankshaw Jr. (Scott Menville)

Plot
Somewhere in space, a Salamandrian fighter force travels through the cosmos, lead by Mona Lisa and Sal Commander. However, their general R'Kavaka soon comes on with news that a rogue Salamandrian, whom Sal Commander has a grudge against as it was that rogue Salamandrian who cost him his left eye, had been spotted on Earth. Realizing Earth is where Raphael lives, Mona and Sal Commander break off from the fleet to head to Earth.

In New York City, Raphael is disgusted by how each of his brothers has a girlfriend, Leo with Karai, Mikey with Renet, and Donnie with April, while he goes to his room to sulk and voice his complaints to Chompy, only to soon get a call over his space helmet from the Fugitoid from Mona, who reports that she is on her way to Earth with Sal Commander. Meanwhile, the rogue Salamandrian attacks three Utrom Normans who arrive to hunt for him, catching them by surprise. When Mona and Sal Commander land and meet up with the Turtles, April, and Karai, they explain why they are there, and the Turtles realize the rogue Salamandrian is really the Newtralizer, going after Utroms without mercy.

Meanwhile, at the Utrom High Council, Queen, Pawn, and Rook are concerned about what's happening, and ask Bishop to investigate. Bishop agrees to take an Earth Protection Force commando team to deal with the Newtralizer and the recent arrivals of Mona and Sal Commander on Earth as well. Soon enough, Newtralizer attacks Sal Commander and Mikey after they split up from Raphael and Mona.

Before going after them, Mona explains to Raphael that she and Sal Commander had to deal with Lord Dregg, who survived his presumed death by the Triceratons, and managed to still launch his invasion of Salamandria. They fought him off, but Dregg swore to return.

After rescuing Mikey and Sal Commander, they are surrounded by Bishop and the EPF commando team. Thankfully, once Raphael and Mikey explain that Mona and Sal Commander are the ones who helped the Utroms previously in Dimension X with the Kraang, Bishop and the EPF release them and agree to aid them against Newtralizer. Despite their best attempts, Newtralizer proves too powerful, and once Leo, Donnie, Karai, and April arrive before Newtralizer can eat Bishop, Bishop has them retreat back to the Utrom High Council chamber, where Rook reveals a device that could help deal with Newtralizer, but he arrives, disables Queen's Miss Campbell body, decapitates Rook, and nearly eats Pawn, before Bishop leads the Turtles and everyone else back to NYC. However, as they fight Newtralizer at a power substation where he fought Leo, Karai, Donnie, and April earlier, where April weakened him with water, he manages to apparently electrocute and disintegrate Mikey. Enraged, Raphael zaps him with Rook's weapon, but before it can destroy him completely, electromagnetic interference saves Newtralizer.

The reason soon presents itself: Newtralizer's old friend and ally, and the one that the Turtles hoped they would never see again: Lord Vringath Dregg, now in a new living command ship, which quickly begins laying Vreen eggs to begin taking over the city. As Newtralizer retreats to the ship, the Turtles, April, Karai, Salamandrians, and Bishop look up in disbelief and shock as things have just gone from bad to worse...

Trivia

 * This episode reveals the following:
 * G'Throkka has a bionic eye because Newtrailzer took out his real one and left him to perish by his wound.
 * Michelangelo has kept in touch with Renet since their last encounter in "Tale of the Yokai".
 * Salamandrian's are forbidden in Earth's galaxy.
 * Lord Dregg survived after being sucked out into space by the Triceratons in the episode "The Ever-Burning Fire".
 * When April uses water to short out Newtralizer's tech, she creates the illusion that she's waterbending, similar to Katara from Avatar: The Last Airbender, who Mae Whitman also provided the voice of.