This way is much easier then using nimpo, he might look tough but he is owned by the bow, make sure that you have the bow in your inventory (kindly donated by a dead ninja)and the max of 15 arrows ( pick these up from the dead ninja in the clearing where you fight the three samurai warriors ) when you confront him pump him with all 15 arrows and this will take most of his life then just go for the kill, N.B if you find yourself short of life then just kill his little floaty friends to get blue eccence.