How in the fuck do you beat Nohr Chapter 8 on hard? I'm seriously considering dropping to Normal, Christ.
Don't power through, its better to keep the group together, try to take down enemies one by one. Save the boss for last after you manage to clear the whole area (that's what I did). The boss hits really hard, I had to reset twice for myMU not to die. My 3 highest units for that battle was a lvl 11 Effie, lvl 10 Silas and lvl 12 myMU. I just made sure to work my way around by keeping Effie in front for tanking then snipe the rest.
Tip: keep danger zone on (press x), it helps you plan out your moves and to think ahead so you don't get into tight spot.
Edit:
I also had Felicia as my secondary healer, having that back-up healer to Elise was a great help.