Busoshoku: Kaito

Busoshoku: Kaito (武装色 外套, Busō-shoku: Kaitō; literally "Color of Armaments: Cloak") is a form of utilizing created by Fleet Admiral Kurama.

Overview
According to Kurama, the basic form of using Busoshoku Haki is far too "rigid", as it eliminates flexibility in one's movements and requires one to create "creases" in the Haki in order to be stretched out. The Haki is compressed to such a degree that it hardens as a black sheet around the user's body and coats their limbs to strengthen their physical strength and durability. However, in the process, this imposes rigidity in one's actions and requires a high degree of concentration that distracts from battle focus. Because of this, Busoshoku Haki can only be used in "bursts" rather than in continuous action. In the hopes of finding a solution to this that would allow those under him to fight more efficiently, Kurama created a more flexible approach.

Focusing on the concept of Busoshoku Haki being an invisible force that coats the body, Kurama invented a technique to expanding the aura of the Busoshoku Haki through advanced breathing techniques found in ancient martial arts that would allow Haki users to synchronize their will with their breathing. In doing so, by first compressing the Haki and then expanding it outwards by conceptualizing their body as the center, it would be possible through the proper training and practice to maintain a steady expansion that would manifest as a permeable aura that would be liquid in appearance and coat the entire body of the user like a cloak. In doing so, not only could the strength and durability of Busoshoku Haki be utilized with minimal focus, as it has become linked to one's breathing, but also allows for maximum flexibility.