Chopper deduces that Oars originally died from frostbite 500 years ago in the Land of Ice.
In , the "useful feature" refers to Gecko Moria's ability called Shadow Revolution . Shadow Revolution: Moria’s Manipulative Power
The episode concludes with the debut of , who arrives to challenge Moria and Oars. One Piece Episode 371
Moria also uses a useful defensive feature of his Shadow-Shadow Fruit powers to instantly switch places with his shadow, Doppelman , allowing him to evade attacks—such as when he rendered Nico Robin's Clutch attack useless by swapping locations with his shadow. Episode Overview
Moria uses this "feature" to make the giant zombie, Oars, stretch his limbs just like Luffy. Normally, Oars is a giant who cannot stretch, but Moria extends Oars' shadow, which forces Oars' physical body to elongate to match the shadow's shape. Chopper deduces that Oars originally died from frostbite
Moria systematically takes down several Straw Hats, including Nico Robin, Sanji, and Chopper.
During the battle against the Straw Hat Pirates, Moria demonstrates that by manipulating a person's shadow, he can force their physical body to change its shape as well. Moria also uses a useful defensive feature of
Gecko Moria & Oars vs. the Straw Hat Pirates. Plot Highlights: