>>166 I do have to correct myself
Jack did kill by accident, and later to defend himself from the sisters, recalling his father's words during just post Sengoku Era (implied since his father was an Emperor, and those were Shinobi attacking him).
Even artistically and canonically, it's implied Jack is Honda Tadakatsu/本多忠勝
But I mean it more symbolically than anything. The wikipedia entries suggest they might either make more than the 9 episodes with another season, or just finalize it with a movie.