"Who would have thought that we’d still be finding out new things about Final Fantasy IX, 13 years after its release?
Final Fantasy IX must be the Final Fantasy that keeps on delivering. A few months back, the ninth entry in the series received attention for an undiscovered sidequest. Now there’s been another discovery made, though this one contains some spoilers regarding the game’s final boss.
Adventurous completionists will recall being able to fight a hidden boss named Hades, who in typical Square Enix fashion was incredibly hard to beat. Hades has actually popped up several times throughout the series as a summon tied to darkness and status-effect magic, most notably in Final Fantasy VII.
According to newly released concept art from Final Fantasy 25th Anniversary Ultimania, a book that examines series backstory and production lore, it turns out that Hades was originally considered as the game’s ultimate foe." - Maxwell Coviello