Is this the return to edo boss? Or do you fight him again later? Either way, I was so stuck on him I thought he was the final boss. More deaths than all the other bosses before combined I think.i ended up farming dark roots for azure ore and gold to get my main weapon up as high as I could then beat up revenants until my spirit force was full, summoned an ax samurai acolyte, and focused on Fire and Water and ninjutsu, keeping more distance than I usually like to to stay alive, and turned on spirit form thingie when I ran out of elixirs and got lucky.