Mukōjōchū Muramasa

is a technique of Kōga Kuchiki's Zanpakutō, Muramasa.

Description
Raising his Zanpakutō so the blade points directly upwards, Kōga calls out the name of the technique, creating a massive explosion of purple Reiatsu. As the dust clouds settle, Muramasa begins to manifest, initially covered in a purple haze which disappears as he becomes a physical presence. Muramasa is now able to use his abilities on Kōga's foes directly. Muramasa can appear wherever and whenever he wants, without Kōga having to perform the technique, due to this ability.