The seven Deus-Excellion were constructed to seal and serve as a receptacle of the Great One's power, the ultimate yet unstable power that was born from the fusion of the Sept-Terrions of Blaze and Earth. The Deus-Excellion were originally equipped with system to think on its own, and would be influenced by the actions of mankind. Under influence of humanity's bad faith, however, Ishmelga involved into a unique spiritual lifeform.[Note 1][JP 3] In order to become a god-like entity with absolute power as much as possible, it spreads that bad faith throughout Erebonia in the form of a curse.
Ishmelga succeeded in making one half of its creators, the Gnomes, its underlings which would continue to support it throughout history. In S.371, Ishmelga's dominance over the Gnomes was the likely cause of the Gnomes' declaration of separation from the Hexen Clan and their withdrawal to the background. Using the Gnomes, Ishmelga continued to work on weaponry needed for the Great Twilight and areas required for the Rivalries. Ishmelga eventually dominates the soul of Franz Reinford, reawakening him as the Gnomes leader Alberich.
As a Divine Knight, Ishmelga was unable to use its full power without an Awakener. Ishmelga's eye fell on triumphs of Dreichels Reise Arnor during the War of the Lions and became obsessed with his soul. It persuaded the emperor to become its Awakener until he died of old age. Two hundred years later, it turned its attention to Dreichels's reincarnated soul in Giliath Osborne. Ishmelga manipulated the curse into the raid on Osborne's house. In a desperate plea to save his son, Rean, Osborne agreed to become Ishmelga's Awakener.
With the Gnomes as its loyal kinship and Osborne as its Awakener, Ishmelga's final aim was to accelerate the Great Twilight in order to become the Great One. By spreading the curse and initiating the Great Twilight, the conditions for the seven Deus-Excellion to engage in the Rivalries were met. It aimed to use the Rivalries to absorb the power of the other Deus-Excellion, restore itself to the Great One and gain world domination.
Ishmelga's plan came in jeopardy during the final Rivalry, in which the Rean Schwarzer-piloted Valimar got the better of the Giliath Osborne-piloted Ishmelga. At the final moment, Ishmelga abandoned the Black Deus-Excellion and targetted Rean, who as the true sacrifice had already been marked as a spare for Osborne. Ishmelga's thoughtform, now obsessed with the young Awakener, fused and took over Valimar. Both Rean's skin and Valimar's exterior became defiled by Ishmelga.
In the true ending of Sen no Kiseki IV -The End of Saga-, Argres's blessing as the Holy Beast of Earth dispells Ishmelga's binding spell on Franz Reinford. With his advice and the support of his friends, Rean manages to seal Ishmelga's thoughtform and the nearly completed Great One in the Cage of the Earth.[JP 4] As the final Rivalry took place earlier than Ishmelga had planned, Ishmelga re-emerged as an incompletely manifested Great One known as Ishmelga-Loge and the one form that makes it vulnerable in the current dimension. After struggling against Rean and his friends, the Great One was defeated at long last.
Having lost the Great One's vessel, Ishmelga returned to its shadow-like existence of a thoughtform. Ishmelga insisted that humanity managed to grow thanks to its efforts to instil the general notion of strife and asks for forgiveness. Rean acknowledges that humanity did indeed grow through Ishmelga's efforts, but also claims that while the opposing natures of mankind that brought forth Ishmelga, which in turn stimulates further strife, they still aim for for the possibility to reach new heights. He even likens Ishmelga to a god-like entity that passed down blaze and wisdom to the people.
Rean ends Ishmelga's existence with a single strike.
Ishmelga was responsible for multiple events in Erebonia's history, including but not limited to:
- S. 371: The Dark Dragon's Arrival
- S. 470: The cursing of Argres and Testa-Rossa
- S. 527: The Dark Ages War
- S. 947: The War of the Lions
- S. 1192: The Hundred Days War
- S. 1204: The Occupation of Crossbell
- S. 1205: The Northern War
- S. 1206: The Great Twilight
- S. 1206: The World War
- ↑ The games do not address the nature of this bad faith. Negative feelings that would lead to aggression toward others, the encouragement of strife Ishmelga came to embody, may have included anger, hatred, jealousy and inferiority. It may be possible that after the war between the Kinship of the Earth and Kinship of the Blaze around the Great Collapse, some may have had resentment toward the other kinship during the construction of the Deus-Excellion.