Ultra Galaxy Legend Gaiden: Ultraman Zero vs. Darklops Zero is a two-part tokatsu film produced by Tsuburaya as part of the Ultra Series, and is a direct prequel to Ultraman Zero: The Revenge of Belial as well as a sequel to Mega Monster Battle: Ultra Galaxy Legends.
A routine training exercise had Zero suddenly being assaulted by robotic clones of the Ultra Brothers: Ultraman, Ultraman Jack, Ultraman Ace, and Zoffy. While Zero fends off their attacks, the crew of the ZAP Spacy Pendragon (after their adventures in Ultra Galaxy Legends) gets ambushed by the robotic copy of Ultraseven, forcing them into the same planet where Zero is being ambushed.
After a series of battles, Zero and the Space Pendragon discovers the source of the robotic Ultramen clones to be from an Alien Salome (last seen in Ultraseven) facility on the planet, where the aliens are mass-producing fake Ultramen to take over the universe. Besides the Ultras, the aliens also have their trump card, a robotic duplicate of Ultraman Zero called Darklops Zero, whose Artificial Intelligence is starting to develop a mind of its own...
Tropes related to characters in the film is documented on the main characters' pages.
Ultra Galaxy Legend Gaiden: Ultraman Zero vs. Darklops Zero provides examples of the following tropes:
- Cyber Cyclops: Darklops Zero, whose name is Exactly What It Says on the Tin a dark cyclops version of Ultraman Zero.
- Beam-O-War: Ultraman Zero against Robot Ultraman Ace. Then later Ultraman Zero and Ultraman Leo combine their beams against Robot Ultraman's Specium Ray and Robot Ultraseven's Wide Shot.
- Big Bad Wannabe: The Salomians learn the hard way that you do NOT attempt to harvest an Ultraman's powers for your own nefarious goals, lest it comes bite you back it the ass. Nor do you try to boss around someone stronger than anything you've built.
- Big Damn Heroes: Ultraman Zero, about to be overwhelmed by the robotic clones of Ultraseven and Ultraman, when suddenly... who is playing the Ultraman Leo theme in the background?
- Dragon Ascendant: Darklops Zero, who wipes out the Salomians single-handedly after realizing its being used as a pawn by the aliens.
- Disney Villain Death: The Salomians. The two henchmen Irate and Ganetsu gets crushed by rubble, while the Big Bad Herodia simply falls to her death.
- Greater-Scope Villain: Ultraman Belial does not show up, but he is the creator of this Darklops Zero, who is only one of many more under his rule.
- Earth-Shattering Kaboom: After Zero inflicts a mortal injury on Darklops, the robot detonates the core in its chest in a Taking You with Me moment, effectively nuking the uninhabited planet it's standing on.
- Evil Is Not a Toy: As Alien Salome Herodia finds out, an evil robot made in Zero's image that came from another universe is not hers to control.
- Evil Knockoff: Darklops Zero to Ultraman Zero, and Mecha-Gomora to Gomora.
- Kaiju: The film has Rei's Gomora and Litra returning on the heroes side as usual, with Mecha-Gomora serving as the film's central Kaiju antagonist.
- Mechanical Monster: Well... ALL the villains except the Salomians. Mecha Gomora, Darklops Zero, the Robot clones of the Ultra Brothers...
- Offscreen Moment of Awesome: Ultraman Zero's battle against Robot Zoffy and Robot Ultraman Jack, after the title credits the camera pans down to reveal Zero have already defeated them.
- Oh, Crap!: Herodia's reaction when she realized Darklops Zero isn't a mindless robot, the moment Darklops removes its own Techtor Gear Armour.
- Significant Anagram: The Salome henchmen, Irate and Ganaesu, have their names derived from their respective actors, Daisuke Terai and Hiroshi Suenaga.
- Super Prototype: The Darklops as seen in this film is a Prototype and the most powerful of its kind overwhelming Zero in their first fight and having a planet-killing bomb installed inside of it; subsequent Darklopses would show up later in the series but those are hardly as powerful as the one here nor do they have planet-killing superweapons installed for a last-ditch move.
- Sweeping Laser Explosion: Darklops Zero's destruction of the Salome Aliens' robot-creating facility is depicted in this manner, where a single laser fired from Darklops Zero's eye cause a chain of explosions behind everywhere it passes until the entire facility is reduced to ruins.
- Turned Against Their Masters: Darklops Zero turned against the Salomians at the end of the film, though they were not his masters to begin with... As his true master was Kaiser Ultraman Belial.
- Unwilling Roboticisation: It turns out Mecha-Gomora used to be a normal Gomora, before getting forcibly converted into a mechanical version of itself.
- Versus Title