Final Fantasy 14: A Deep Dive Into Zodiark

gamerant.com:

Throughout Final Fantasy 14, Zodiark is an imposing force of darkness against the Hydaelyn goddess. While its name has been invoked by Ascians since the beginning of the MMO, it was not until Shadowbringers when players really got to understand the lore around this ancient primal. In Endwalker, many expected Zodiark to be the final boss, but it turned out to actually be the first trial boss.

The lore in Final Fantasy 14 is complicated, so much about Zodiark gets lost in all the stories of the Ascians, the Final Days, Etheirys, and Hydaelyn. Despite being an embodiment of darkness, which most connect to evil and death, the primal was made to save the ancients and Etheirys from the Final Days. However, to Eorzeans, the primal is the root of their many Calamities and troubles.

Final Fantasy 14: The History Of Gridania

To know how Zodiark works, it's important to understand how the primal was made. The primal was created during the «Final Days» in Etheirys. The Final Days was a stagnation of aether that caused creation magic to warp into monstrosities that killed everyone. The ruling body of Etheirys was the Convocation of Fourteen, and they came to the conclusion to create Zodiark, a primal that could «weave the laws of reality anew,» which would solve the stagnation of aether. Half of the population of Etheirys willingly sacrificed themselves to create Zodiark. Zodiark needed a core that would be its personality, and Elidibus of the Convocation of Fourteen volunteered himself, after Loghrif was convinced not to.

Zodiark worked in stalling the Final Days, as it was able to make a barrier that replenished Etheirys' aether. However, more sacrifices were given to Zodiark in an obsession for the primal to restore Etheirys.