Zeorymer

Hades Project Zeorymer is a manga by Yoshiki Takaya (better known as the creator of Guyver), written under the pen name Chimi Morio, and published in the adult manga magazine Lemon People from October 1983 to November 1984. A three-part finale was serialized in Monthly Comic Ryū in 2007. A four episode OVA adaptation by AIC tones down the explicit sexual content and deviates entirely from the manga storyline and setting.

Set in the near future, a secret feudal monarchy led by an empress and named 'Hau Dragon' uses, as a front, a firm 'International Electronic Brains' and has built a set of eight giant robots, each possessing a power based upon the eight elements of earth, fire, water, air, thunder, mountains, the moon and the heavens. However, one of them, Zeorymer of the Heavens, has been stolen and the main character, fifteen-year-old Masato Akitsu, is forced into piloting it with a mysterious girl named Miku Himuro.

Zeorymer possesses an energy based weapon called the "Dimensional Coupler Cannon" that appears almost telekinetic in nature; by holding its fist in the air, or aiming it at a target, energy strobes across the orb and causes a large explosion to engulf whatever enemy it is directed against. These orbs can also fire beams of golden-hued energy (labeled as the Energy Wave attack) which can cause massive damage, and project a forcefield which seems nearly impenetrable. The robot itself is also incredibly durable: in the third episode, it was struck with a weapon that left an effect similar to that of a nuclear warhead, yet suffered only minimal damage. Zeorymer of the Heavens is able to hover, fly, teleport unspecified distances, and possesses an incredibly potent weapon known as the Hades Attack: when it lifts its arms in the air then lowers them across its chest, slamming its fists together or against the large golden orb on its chest, the robot releases a huge blast of golden energy that, at full power, can cause an explosion visible from space (inferring the power of several gigatons at least, though even on lower settings this final weapon seems equal to most nuclear weapons in scale). When this attack is activated, a mysterious voice, possibly Zeorymer's itself, can be heard saying "Meiou," the attack's name.

Tropes used in Zeorymer include:

All Your Powers Combined: Wakatsuki had planned to fuse both Zeorymers into one better one.
Brain Uploading
Gratuitous Rape: The rape scene has no plot relevance, is not even acknowledged by the characters, and makes it hard to like the main character even after his evil side loses the battle for control.
Healing Factor: Zeorymer can repair itself using parts from another dimension. It can even regenerate the pilot if he's killed.
Heel Face Turn: Golshid.
Invincible Hero: Zeorymer, as long as the Ultradimensional System doesn't crap out.
Load-Bearing Boss: Wakatsuki.
Name's the Same: Masaki Akitsu and Masaki Wakatsuki.
Powered by a Forsaken Child: The Ultradimensional System's key component needs to be kept in Miku's uterus for some reason, and Zeorymer keeps poking her... Look, it's a Super Robot, it doesn't have to make sense.
Spanner in the Works: Prof. Himuro attempts to sabotage Zeorymer as revenge on Wakatsuki, but realizes he didn't need to. Later it's revealed that Zeorymer recognizes Akitsu as its master, leaving Wakatsuki helpless.
Split Personality Takeover: For a while. In truth, Zeorymer only gave Wakatsuki's memories to Akitsu. Once Akitsu adjusts to this, he goes and saves the world.
Your Head Asplode: Golshid hits Akitsu with a J-Kaiser to the face. He gets better.

The OVA provides examples of:

All Your Powers Combined: In Super Robot Wars Judgement, Great Zeorymer comes equipped with the best attacks of all eight Hakkeshu machines, even the one that's techically a Combination Attack, which just means it creates another copy of itself out of nowhere.
Anti-Villain: In the anime, the Hakkeshu and Empress Yuratei are, with the exception of Ax Crazy Saiga, really not that bad of people, except for the fact they want to destroy the world. A Hau Dragon scientist even remarks they really aren't the kind of people that have any reason to be the villains in the story.
Big Bad: Masaki Kihara, the creator of the Hakkeshu machines. In the manga, it turns out that he's still running the show despite being thought dead. In the anime, he's set up a nice little Xanatos Gambit.
Bishounen: Ritsu the guy with the mask. He hates it. Slight distinction in that he isn't simply feminine-looking. He has an actual woman's face.
Brain Uploading
Boring Invincible Hero: Zeorymer, at least when Miku attached to the main power drive.
Dysfunction Junction: The Hakkeshu are all these. Masato and Miku are both the most doormatty of Extreme Doormats, Taiha feels guilty about not caring for his lover the same extent she does to him, twins Shi-Aen and Shi-Tau have horrible teamwork due to Shi-Aen's detached nature and Shi-Tau's jealousy, Ritsu has an inferiority complex due to bishie good looks making everyone think he's a woman, Giso was hopelessly a Romantic Runner-Up, Rokfel couldn't see Giso's dependability and loved the jerkass Saiga, and Saiga is the only person in the entire series that's more of a Complete Monster than Masato is when he goes psycho. Justified in the fact that their creator wanted them that way so he'd have weaknesses to exploit.
Genetic Memory
Grand Theft Me
In Name Only: The only things shared between the original manga and the OVA are Zeorymer of the Heavens and the name of a female character.
- Rose C'est La Vie, Lanstar, and Burston are also included.
My Death Is Just the Beginning
Phlebotinum Rebel
Quirky Miniboss Squad: The Hakkeshu
Red Oni, Blue Oni: Color Inverted: Bryst Of The Fire's pilot is the level-headed one while Gallowin of the Water's pilot is the hot-headed one.
Robotic Reveal: Miku
Shut UP, Hannibal: When Masato is possessed by his evil personality (/ the scientist who stole Zeorymer), he tells the last 3 Hakkeshu that they are clones derived from the same zygote. Rockfell says it does not make any difference. She does a Heroic Sacrifice, even though she is a Designated Antagonist / Anti-Villain.
Spanner in the Works: Unfortunately for Masaki... he didn't quite think out the "brain uploading" function in Zeorymer, so even though Masato starts acting like a Complete Monster, the effect is more or less temporary. Ultimately the two personalities merge, leaving a new person with both decency and confidence.
Sphere of Destruction: Meiou. *cue Stuff Blowing Up*
Split Personality Takeover
Stuff Blowing Up: Zeorymer's specialty.
Super-Powered Evil Side
Super Robot Wars: MX and J, though only the latter game adds in Great Zeorymer as a secret unit.
Talking the Monster to Death: More like talking yourselves to death in the anime. Most of the time in the fights deal with the Hakkeshu ranting to Masato or each other for various reasons. And then Masaki takes over, uses "Meiou" and wins without any effort.
Tyke Bomb: The Hakkeshu, Masato.
Wave Motion Gun: Rose C'est La Vie's J-Kaiser. Wouldn't you know it, Great Zeorymer also has this in its arsenal.
We Can Rebuild Him: More like "The Dimensional Coupler System can rebuild him"
Xanatos Gambit: Masaki genetically engineers the Hakkeshu and Empress Yuratei before having to flee from Hau Dragon for whatever reason. He provides the Japanese government with Zeorymer before getting killed, but Yuratei and Masato both are potential vessels for him to control. From there he merely has to wait until either the Hakkeshu or Masato-as-Masaki gets the opportunity to conquer the world.