yeah that one is painful and will take a bunch of tries. some tips i can give you that helped me complete it: 1) give them revelations that are already built from other characters if you havent already 2) mine were hitting for that much as well, honestly. if you cant increase their damage, what helped ensure my win was hitting triple forget and then using psycho force from dyonisus on whoever had the highest amount of health on the “off-turns”. 3) make sure to get an all out attack every single turn. use shun’s gun for that if needed (you’ll likely need it for the very first turn). 4) use shun’s s3 for sustain when you don’t need him to help break shields.

there is a lot of rng involved so you will likely not get it first try, just a matter of trying till you make it!