In Final Fantasy X, what is the name of the hidden superboss in the Omega Ruins?

In Final Fantasy X, the hidden superboss in the Omega Ruins is Omega Weapon.

Omega Weapon is an optional endgame boss found in the Omega Ruins, a secret dungeon accessible through the airship’s location search. The ruins are associated with Omega, a former religious figure who was branded a traitor by Yevon and exiled. According to the game’s lore, his hatred and resentment eventually transformed him into the fiend known as Omega Weapon.

Players often confuse this battle with Ultima Weapon, a separate and weaker boss encountered in the same dungeon. Omega Weapon is the final major confrontation in the ruins, while Nemesis belongs to the Monster Arena and Penance is an additional superboss introduced in enhanced versions of Final Fantasy X.

The challenge also varies by release. In the original North American and Japanese versions, Omega Weapon has 99,999 HP. The International, PAL, and HD Remaster editions raise that total to 999,999 HP, making the encounter substantially more demanding for fully equipped parties.