Enki

Enki (エンキ, Enki) is Viral's personal Gunman, modeled after an armored samurai. The Enki is the product of significant innovation in Gunmen technology, and sports a number of advances that eclipse lesser models in performance, and is the first model seen to support solid-based ammunition. Unlike stout Gunmen, such as the Gurren, that have bulky limbs that can only be used in wide swings, the Enki is more segmented and has multiple joints that allow it to perform complex actions, such as throws, kicks, and various martial arts techniques. The Enki's arm and thigh plates conceal rows of hidden gun turrets that fire large steel projectiles (kunai). There are pop-up compartments in the shoulders that can fire a single volley of rockets, and the entire chest plate can open to reveal a number of launchers that deliver an explosive payload of missiles. The Enki possesses a wrist mounted concave blast-shield, and a helmet with a large black ring atop of it which is actually the charging focus for a medium-range particle beam cannon (Called the Enki Sun Attack in the video game Super Robot Wars Z2 Hakai Hen). Its helmet becomes the possession of Simon and Kamina, as they broke it off and stole it when they first combined to make the Gurren-Lagann, after which the latter mech integrates it as a permanent addition to its armor.

Enkidu
Later, the helmet-less Enki has been redeployed as the upgraded Enkidu (エンキドゥ, Enkidu) and sports a new sickle-like weapon, which is affixed to its head (a homage to Ultraseven 's Eye Slugger weapon). When wielded, it provides an alternative to the dual swords the Enki usually resorts to in melee combat. Furthermore, it is also capable of shelling from afar by physically launching munitions from the same point on its head, once the sickle has been removed. When it is aided by Cytomander's air raid on the Dai-Gurren, it was also equipped with a flight engine, allowing it to fly.

Dai-Gunzan-Du
The Dai-Gunzan-Du {ダイガンザンドゥ Daiganzandu) appears only in the first film adaptation of the series, Gurren Lagann The Movie: Childhood's End. Viral is the commander of this Dai-Gun, to make up for the loss of Dai-Gunzan and Thymilph. Following the pattern with Viral's mechas, it has an extra set of arms like Enkidudu, has the crest of Enkidu, and follows the color scheme of Enki. Dai-Gunzan-Du shares all its abilities of the Dai-Gunzan and can be used as a substitute for the Dai-Gunzan in the Do-Ten-Kai-Zan.

Enkidudu
During the Invasion of Teppelin, Viral's Gunmen is remodeled into the Enkidudu (エンキドゥドゥ, Enkidudu), replacing the sickle crest for an extra pair of arms, meaning the Gunmen can now fight with four blades. When the new form fights the Gurren-Lagann, however, it is swiftly defeated, despite its upgrade. After the timeskip, the Enkidudu is shown fighting the Grapearl unit, in order to protect a group of humans who decided to continue living underground. However, the damaged Enkidudu is unable to hold its own against the advanced Grapearls and is ultimately defeated, shutting down as Viral thanked his mecha for lasting this long for his grudge. The fate of the Enkidudu is never known.

Tengen Toppa Enki Durga
Viral is given his own Tengen Toppa Gunmen during the movie adaption of the final battle with The Anti-Spiral. It sports seven sets of hands, each of which can wield a weapon. It uses twelve blackened blades along with a single kanabō to protect Nia from the Granzeboma, and is later used along with the rest of Team Dai-Gurren's mechs to form the Super Tengen Toppa Gurren Lagann.

Enki
Crested Helmet: Enki has a crest on its helmet which fires a beam officially named the Enki Sun Attack.

Enki Swords: Enki also has swords at the side of its hips which he claims he only uses when he takes a fight as an actual challenge.Arm Shield: Has a built in shield in its arms to protect itself from incoming attacks. This was used against Yoko, when she fired a bullet towards Viral.

Enkidu
Sickle Blade: This is used as a sword as well as a throwing projectile, which presumably can be reformed at the top of Enkidu's head.

Enki Swords: Enkidu still retains its swords at the side of its hips which he claims he only uses when he takes a fight as an actual challenge.

Arm Shield: Has a built in shield in its arms to protect itself from incoming attacks. This was used against Yoko, when she fired a bullet towards Viral.

Dai-Gunzan-Du
Canons: Similar to Dai-Gunzan, Dai-Gunzan-Du also has a multitude of canon's to fire at enemies nigh-omnidirectionally.

Gunmen: This Dai-Gun is also capable of throwing Gunmen to any desired location within its range, for the Gunmen to attack.

Enkidudu
Enki Swords: Instead of having 2 swords like usual, Enkidudu owns 4 swords for each of its hands to utilize.

Arm Shield: Has a built in shield in its arms to protect itself from incoming attacks. This was once again used against the Grapearl in episode 17.

Tengen Toppa Enki Durga
Tengen Toppa Enki Swords: A galactic scale variant of Viral's signature weapon. Pistols: Tengen Toppa Enki Durga wields multiple galactic scale pistols, which were used in the midst of his swordfight against Antispiral's Granzeboma. They were also used to fire against Granzeboma along side most of the team.

Etymology
All forms are based on figures in Sumerian myth: Enki was a god of wisdom. Enkidu, meanwhile, was the wild man who fought and befriended King Gilgamesh during the Sumerian epic. The latter seems to bear significance to Viral's role in later episodes. It is possible that the mecha's name is a reference to French comic author Enki Bilal as Viral can also be read "Bilal" in Japanese. This is further evidenced by the title of Viral's theme, "Nikopol", which is the name of one of Enki Bilal's most famous work, the Nikopol Trilogy.

Trivia

 * In the Drama CD Otoko Ippiki Gurren Lagann, the upgrades were made into a running joke in the form of the six-armed Enkidududu (エンキドゥドゥドゥ, Enkidududu) and the eight-armed Enkidudududu (エンキドゥドゥドゥドゥ, Enkidudududu).
 * In the series itself, a running gag is that Viral's mecha all use black-bladed swords which are invariably destroyed by his opponent, despite Viral himself seemingly considering his swords to be his best weapons.