Jinnai’s sword, Ruretsu , doesn't just grant him power; it physically fuses with him.
Unlike traditional Zanpakutō, the assassins use "Bakkōtō"—swords that feed on the wielder's spiritual energy (Reiatsu) in exchange for massive power. 💡 Interesting Piece: Jinnai’s Transformation Bleach Episode 175
This episode is part of the filler arc. It features a coordinated assassination attempt on the Soul Society princess, Rurichiyo Kasumiōji , while she is hiding in the Human World. Jinnai’s sword, Ruretsu , doesn't just grant him