One Piece's Elbaf Arc secretly dropped a hint that the series' lore is far older than the just the Void Century.

One Piece’s final saga has introduced fans to a ton of exciting lore reveals about the Void Century, with Vegapunk revealing ...

Dark Nika is a concept that is valid due to translation ... Breath stirred within the void, and the Forest God sent forth demons. The Sun did nothing but spread the fires of war.