Oto and Kogarashi

Oto and Kogarashi are a pair of double-edged swords wielded by Shiki. Their shape is quite strange: they have regular tsubas, protruding on four sides, and red hilt wrapping, but their blade is very large and it grows thinner near the tip. Though it is unknown what special properties they have, he notes them to be famous.

In the past, Shiki wielded them as regular swords, but twenty years prior to the start of the series, after severing his legs to escape Impel Down, he grafted both Oto and Kogarashi onto where his missing feet were, and since then they became his prosthetic legs.

The swords ultimately fell with Shiki when he was defeated by Monkey D. Luffy; what happened to them after that is unknown.

Abilities
Shiki has been shown to wield both of his swords with great skill. He was powerful enough to kill a massive amount of soldiers in Marineford, as well as challenge famous characters like Gol D. Roger, Monkey D. Garp, and Sengoku with them.

After the two swords became his new legs, he has shown to be able to send out air-based slashes by kicking with them, similar to the CP9 members' Rankyaku technique. The air-blades have a light-yellow/gold color-scheme, matching Shiki's epithet. He also combines his sword skills with his Fuwa Fuwa no Mi, such as slashing open a body of water and then levitating it to drown his opponents.

Translation and Dub issues
"Oto" literally translates to "Ten Cherry Blossoms", while "Kogarashi" means "Cold Wintry Wind".