Cube (冥界島(キューブ) Kyūbu) is a floating island housing Demons of Tartaros.


Serving as home to Mages of Tartaros, Cube is a massive, buoyant cubed-island that harbors several rocky terrains spread about on its surface. The largest structure is, undoubtedly, one of its many landscapes accommodating Tartaros' headquarters.[1]

Due to its ability to float about freely, Cube's exact location and coordinates are unknown to many, including the Magic Council.[1]

It has been noted that when Face activates upon its seal's release, Cube shakes violently as indication to the Magic weapon's awakening.[2]

Alegria Alteration

After the destruction of Face and parts of Cube due to the Fairy Tail Guild's invasion, Mard Geer used Alegria to change the form of Cube and trap those inside.

As a result of Alegria, Cube is vastly changed in both appearance and size. The outside of the floating island expands dramatically, with the guild building's earthy islands moving to create almost decorative patterns on the surface of the mass, whilst scaly protrusions also begin to appear. On the lower face of Cube, these protrusions take on the form of long, plated tentacles and dark spines, which hang downward and appear as legs. On the top of Cube, the new protuberances look more like the fins of a fish, and flare out on either side of the island almost like hair. In addition, crag-like formations rise from the top of Cube, creating large cliffs that jut from the top of the structure. However, most notably, a section of the lower face of Cube breaks away completely, opening up one of the side faces to resemble a humongous mouth with over-large teeth and fangs. As an entirety, the building resembles a huge Demonic creature and also takes on a new name: Plutogrim (冥王獣(プルトグリム) Purutogurimu).

The inside of the Tartaros headquarters is also altered, with the previously castle-like hallways and rooms being completely melted away. Along with the warping of the different locations in the hideout, anyone present will also be consumed, being dragged down into the melting rooms as the change is under-way. After some time, the liquefied building begins to harden over, re-solidifying and trapping anyone unlucky enough to have been caught up in the transformation.

Despite the grim effects of Alegria, it can be noted that surviving the transformation of Cube is possible, though there is apparently only a one in a billion chance of this occurring.[3]


Locations in Cube
Tartaros HQ
Tartaros' Guild Building


  • The Kanji for "Cube" reads Hades Island.


  1. 1.0 1.1 Fairy Tail Manga: Chapter 367, Page 18
  2. Fairy Tail Manga: Chapter 369, Page 18
  3. Fairy Tail Manga: Chapter 382, Pages 19-27


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