Arc-Gurren

Arc-Gurren, the name coined by Rossiu Adai, is a battleship-grade Gunmen counted among Lordgenome's Dai-Guns, one of the craft his forces flew back when he still fought as a Spiral Warrior before the events of the series. Its bulk is staggering, rivaling the Dekabutsu, and it draws on Spiral Power to run while recognizing only Lordgenome as a valid operator. The ship can endure at least a year adrift in space and carries a wide spread of large-scale defenses and weaponry.

Its great purpose becomes clear when Earth faces ruin. Unearthed beneath Parliament Tower, the vessel is meant to shelter as many people and animals as can be crammed aboard, then orbit the planet for a year while the surface cools from a coming impact. Bringing it online with Lordgenome's severed head as a biocomputer draws swarms of Mugann against Parliament Tower, forcing an early launch into space where still more Anti-Spiral forces wait. As public faith falters, its Spiral output sags and its armor grows vulnerable despite a screen of Grapearl units. When two enormous Mugann corner it, Leeron urges Simon to fuse it with Gurren-Lagann, giving rise to Arc-Gurren Lagann. Afterward the combined giant braces the moon against an early collision, and in time the ship becomes the Ultra Spiral Powerplant driving Super Galaxy Gurren Lagann.

Rossiu Adai commands the vessel as its captain, while the preserved head of Lordgenome functions as its biocomputer and Leeron Littner works among those who bring it to life. Simon and Team Dai-Gurren arrive to defend it during the Mugann onslaught, ultimately merging with it in Gurren-Lagann.