This episode serves as a showcase for his craftsmanship, proving that the Thousand Sunny is far more than a standard vessel.
To escape being crushed by massive ice collisions, Franky reveals one of the Sunny’s specialized features: Soldier Dock System Channel 4 . This introduces the Coup de Burst , a powerful air-cannon maneuver that allows the ship to "fly" over obstacles.
It acts as a "buffer" arc to allow the manga to get further ahead, while also giving the audience a chance to see the Thousand Sunny in action before the high stakes of the upcoming Thriller Bark Arc .
Introduced as the primary antagonists of this arc. They are led by Don Accino, a man with the power of the Atsu Atsu no Mi (Hot-Hot Fruit).
Episode 327 is part of the Ice Hunter Arc, which is original to the anime and does not appear in the manga.