the only known user of this jutsu is Karasūri's a jutsu where the user must reach susanoo's complete form.In this jutsu the user merges his body with susanoo's so he has susanoo's bones and flesh and even his weapons .this jutsu protects the users flesh and bones and organs it's very strong but the downsides is it causes pain if used for a long time and needs chakra to keep it maintained, it also allows the user to open all 8 gates without any penalty beacuse it protects the body.