Jikuu Tenshou Nazca

From Storm in Heaven:
Kyoji is a troubled boy who found peace thanks to his sensei, Tate, and the teachings of kendo. But during a kendo competition, Kyoji sees his master transform into an Inca warrior with eyes full of wrath. The two of them awaken the souls of ancient warriors within them, and start down the road toward repeating the same series of events that occurred in their past lives.