Karakuri Rasento

The name translates to something like trick-mechanism spiral sword, and it belongs to Sasaki of the Beasts Pirates. From outside it looks like a wide-bladed Japanese nandao, dressed with greenish-gray cord wrapping that leaves diamond gaps, gold fittings, a rectangular guard, tufted orange cords, and a matching sheath whose coloring shifts to blue in the anime. Its true nature only shows once the blade leaves the scabbard.

Drawn, the sword reveals a single-edged blade lined along one side with rows of smaller flap-blades set in diagonal segments, each bearing its own wavy temper line. When Sasaki engages the rotating mechanism, those flaps swing out perpendicular to the main edge and begin spinning at high speed, leaving the whole weapon shaped like a drill. That drilling spin amplifies the force behind his swings, letting him overpower General Franky in a clash and slice its Franken apart. He can also swing the blade while aloft in his half-triceratops form, granting him an aerial fighting option. His technique Heliceratops sees him dive from above on his propeller frills and rake an enemy with repeated diagonal cuts, first unleashed on the Gifters of his own Armored Division after Tama's power turned them against him.

Sasaki is the lone wielder of Karakuri Rasento. A fellow Beasts Pirates headliner, Holed'em, owns a separate mechanized blade he calls Karakuri-to, though its abilities remain largely unknown beyond the whip-like stretching the anime grants it.