This boss is the easiest of them all. All it takes is ONE fully charged Akujiki slash to rid him. The best thing to do is to gather all the dogs together and then use a Shuriken Burst. Tate all the dogs and tehn just run up to the boss and slash him once to end the battle.
It may take numerous tries because the dogs are a pain to Tate but it's worth the one-hit kill.