The Kessui is a peculiar-looking naginata (a Japanese halberd), with an extra-long spear-blade attached to each end. Each blade is an actual katana, complete with the hilt and guard, effectively making this two katanas linked together into a spear. With two blades and a long reach, Kessui can be a powerful weapon.
While Hannyabal usually carries a pitchfork during his round of duty, he has never been seen using it (except during the anime, to fend off lesser foes), yet he is not seen holding Kessui around with him until he truly needs it, suggesting that Hannyabal only brings out the double-bladed naginata as his trump card.
Hannyabal has shown to be very skilled wielding Kessui, but seems to save its usage for when he deems it necessary. With a long blade on each end, he has a very long attack range. He could spin it rapidly to create flames from friction to deter his opponents. With this, he formed one named attack, as listed below:
Hannya Carnival: Shonetsu Jigoku Guruma (ハンニャカーニバル 焦熱地獄車,Hannya Kānibaru: Shōnetsu Jigoku Guruma?, literally meaning "Hannya Carnival: Blazing Hell Wheel"): Along with fanfare being played by guards alongside him, Hannyabal twirls the sword in such a way that it creates two flaming wheels at his sides. In the Viz Manga, this is called Hannya Carnival!! Inferno Hell Wheel. In the anime this is called Hannya Hustle Dance: Shounetsu Jigoku Guruma. In the FUNimation subs, this is called Hannya Hustle Dance: Inferno Hell Wheel. This was first seen used against Monkey D. Luffy.