The Galactic Spiral Abyss is an area created by the Death Spiral Machine. Spiral Warriors that have had their Spiral Power drained by the machine die and their Gunmen become unable to function. For this reason, the Anti-Spiral refers to the abyss as the Spiral Graveyard.
In the First Anti-Spiral War, several Laganns end up in the abyss after their pilots are killed by the Death Spiral Machine. During the Second Anti-Spiral War, the Death Spiral Machine is destroyed by Kittan Bachika's King Kittan Giga Drill Break, causing the Galactic Spiral Abyss to cease to exist. However, the Laganns that were in the abyss remain intact and are later used by Team Dai-Gurren to create Tengen Toppa Gurren Lagann.