Ancestral Weapons of the Mantis

Ancestral Weapons of the Mantis was a strange curved sword with a serrated edge that was reminiscent of a praying mantis' claw and a similarly curved shorter blade make up the pair of weapons.

Sixth century
In 511 the Mantis Clan Champion Yohihotsu ordered to forge them to help the Mantis defend themselves in trade and battle. The curved design intimidated duelists, because they would not know how to respond to them weapons, giving the Mantis advantage in negotiations.

Forewarning
The weapons rested in the temple of Kaimetsu-uo Seido since 1133, when Moshi Wakiza in her deathbed pointed to the weapons dooming the Mantis unless they could be wielded by a "prodigy of sword and spirit".

Abilities
The sword, Sakusen, and the knife, Shoubai, were balanced much like a katana and wakizashi, but they were oddly curved compared to typical Rokugani blades. They enhanced the abilities of Kenjutsu and trade respectively.