Sen no Buki (Literally meaning, "A thousand weapon") is a powerful technique created by Tosen, the idea was for Tosen to detach certain parts of his body such as teeth, nails and hair after hardening them using Busoshoku Haki and then control them using his devil fruit's ability and use them in battle as weapons. Thanks to tosen's mastery over Life Return he can lengthen his nails and hair to create great amounts of weapons from them, which is the reason to why the technique is called "Sen no Buki" (a thousand weapon). There are countless ways of using this technique, such as: