The ‘Iron Fist’ Netflix series has been given an 18 Certification by the BBFC. This is equivalent to an NC-17 rating - strictly adults only. The only other Marvel show to get an 18 certification was ‘Daredevil’ Season 2, which had extreme violence during a Punisher prison scene. Even the scene in ‘Daredevil’ season 1, where a head is crushed in a car door, was only rated 15. This should give some insight on what to expect from the series!