So before the 2.0 update, the final instance in chapter 8 was pretty straight forward, in fact, it was so straight forward that you could auto it all with the right team...however, whether it was intentional or a bug, it seems the 6 pains have been made STRONGER, before the update it was a level 80 fight, however, it has now become a level 90 fight and without the pose of duel passive on earth main rendering all damage at the beginning down to 0, this fight is now close to impossible unless you are level 85 with full cultivation and awakening.
By the way, I know this shouldn't be under "events" but it's the most suitable option since I'm not asking for help or talking about any of the main characters.