Installment 228 - The Mystery of the Devil's Fruit! Luffy and His Team's Supreme Challenge

Episode 228
The Devil’s Fruit’s Secret! Luffy and the Crew’s Ultimate Test
Japanese: 悪魔の実の秘密！ルフィと仲間たちの究極の試練
Akuma no Mi no Himitsu! Rufi to Nakama-tachi no Kyūkyoku no Shiren

The crew meets a mysterious figure tied to the island's secret past. This individual holds important knowledge that could change the course of their journey. The Straw Hat Pirates must protect this person from a faction bent on keeping the truth hidden. The episode focuses on the weight of knowledge and the danger that comes with it.