Episode 858 - The Ultimate Clash to Defend the Pirate Sovereign's Dominion

Episode 858
The Final Battle to Protect the Pirate King's Throne
Japanese: 海賊王の座を守るための最後の戦い
Kaizoku-Ō no Za o Mamoru Tame no Saigo no Tatakai

The crew faces off against the Sea Kings, an organization with deep knowledge of the Lost Sea and the One Piece’s power. As Luffy and his crew battle the Sea Kings, they uncover more about the true nature of the Grand Line’s mysteries and how they relate to the long-lost history of the world’s greatest treasure.