Ryuuseisui is a meteor hammer wielded by Suboshi in the original series, Ryuusei Den, and OVA 1. Incredibly destructive and deadly, it allows its user to deliver swift blows with its two spinning, flying hammers.
Based on the ancient Chinese weapon, the meteor hammer, the Ryuuseisui would traditionally be wielded by its user wrapping the chain or rope around their body before using the momentum of the two swinging hammers to strike at its target. However, Suboshi's skill with the redesigned meteor hammer can be attributed to his Celestial Warrior status, as he controls the two hammers with his mind, forgoing the need to bend and move around with the weapon.
Season 1: Suzaku
When Tamahome and Miaka witness the dead bodies of Tamahome's siblings and father, Suboshi reveals himself to be the one responsible for ther death. Both enraged, Tamahome and Suboshi rush at each other. Suboshi says that Tamahome deserved the death of his family, equalizing to the death of Suboshi's twin brother,Amiboshi, who drowned at the river. Suboshi was thinking that the Suzaku warriors killed him on purpose.
Season 2: Seiryuu
Tomo and Amiboshi were at the cliff when Miaka was trapped into a world of illusions created by Tomo. Suboshi sees Amiboshi wounded by Tomo, and he quickly used Ryuseisui and killed him.
Suboshi went to the real world with Yui, and Suboshi spotted Miaka, so he fiercely ties her down with Ryuseisui in the place where they were in front of many people. Then Tamahome battles Suboshi, with the same audience. His weapon also can come off the rope to witch it is attached and chase its target till it hits, as seen in the battle with Tamahome.