- Name: Sennami Yokazan (千波ダーク炎スラッシュ, lit. Thousand Waves Dark Flame Slash; "One Thousand Waves of Shadow Flame Slashes")
- Type: Ninjutsu; Yin and Yang; Long Range; Offensive
- Rank: S
- User: Seireitou Kawahiru
A variant of Seireitou's signature technique, the Sennami; Sennami Yokazan forms a black flame orb around Seireitou that is shaped like whips circling him. These whips find their origin from the Sennami's focal point; Seireitou's palm. These flames are not normal flames, for they are not created from fire but from the yin and yang energies around Seireitou. With a flick of his wrist, he can send off several senbon-shaped projectiles from the Sennami's focal point, that move at light speed. When they make contact with something biotic, such as humans or animals, the flames from the attack begin to eat away at their biological parts; namely, they began to corrode at the body of the inflicted until they are completely dissolved. Per senbon, the flames themselves only cause insignificant amounts of damage on their own, but once they began to build up; it may completely dissolve an opponent to ashes.
Seireitou can also increase the range of his Sennami Yokazan by using form manipulation to extend it into a blade up to 10 meters in length. This blade is capable of splitting into multiple additional blades upon contact with an enemy, drastically increasing the number of wounds it can inflict. However, each of these additional blades is proportionally stronger than individual Sennami Yokazan senbon. Like the Sennami Yokazan senbon-related technique, this form of Sennami will corrode any biological substance it makes contact with.