- "Sabi" (さび/錆?) means "rust" in Japanese.
- In the Viz manga and Funimation dub, it is called the Rust-Rust Fruit.
Strengths and Weaknesses
The major strength of the fruit, so far seen, is that the user is able to rust and pull apart metallic weapons such as swords. Doing so apparently gives the user somewhat of an advantage against sword-wielding opponents.
In the anime, it has been shown the powers of the fruit give the user a permanent defense against swords and other metal weapons. A sword simply touching the user's body will immediately rust and come apart before a cut can be made. It has also been shown in the anime that the powers of the fruit can also affect the human body.
However, if used on a living thing, the rusting effect seems to be reversible for as long as it does not entirely oxidize the entity in question, since Zoro was seen reverting quickly back to normal after Shu's grip on him was thrown off by Usopp's projectile. Apart from that, the fruit so far does not seem to have any specific weaknesses outside the standard Devil Fruit weaknesses.
Concludes non-canon section.
The fruit's bestowed powers, as used by Shu, have so far been used for both defensive and offensive purposes. Shu has used the powers of the fruit to rust the Yubashiri of Zoro after catching it in his bare hands. He was then able to pull apart the sword as if the sword was nothing.
Anime and Manga Differences
In the anime, this ability causes the rusted metal to dissolve into nothingness instead of falling apart. Also, Shu was able to use the powers to unconsciously defend against one of Zoro's attacks with a cutlass. Right after that, Shu demonstrated that he was also able to use the powers as an attack on living targets, which is also not in the manga; by touching Zoro's arm, Shu was able to rust Zoro's own flesh. Fortunately, Shu was knocked out by one of Usopp's attacks before Zoro's body could become completely covered in rust. After being separated from Shu, Zoro's body was able to return to normal.
- One Piece Manga and Anime — Vol. 44 Chapter 426 (p. 13) and Episode 309, Zoro vs. Shu
- SBS One Piece Manga — Vol. 47 (p. 46), Fan Question: What are the names of the Devil Fruits the Marine HQ captains and commanders, that fought the Straw Hats in Volume 44, had?
- One Piece Yellow: Grand Elements, Shu's and his fruit's names are revealed.
- One Piece Anime — Episode 309, Filler part of Zoro vs. Shu
- Rust – Wikipedia article about rust.