Samurai Deeper Kyo Vol 5

Samurai Deeper Kyo Vol 5 by Akimine Kamijyo. An Action manga rated Older Teen, published in English by Tokyopop in 2004.

Four years after the Battle of Sekigahara, a gentle medicine peddler named Kyoshiro is hiding a deadly secret: he shares his body with Demon Eyes Kyo, a legendary killer who wants his own body back.