Juno is useless this world bossMercury is useless if Slide is not awakenNeamhain is uselessPut Maat or/and Pomona instead of Neptune Move all attackers bottom sideFree slots you can put Ganesha, Medb, Failnaught, Rusalka, Sweet Sytry, Bathory
You can also tinker with your formation. Back row top left to right could be Lupin and all your attackers. Least import units like maat and mars should be on the bottom right. Also many buffs only effect 3 attackers so a 4th attacker is generally not great if you have a support or debuff unit to replace it
try this build I'm getting around 16.500.000 sometimes more
Your team has more power than mine by 3,000.That being said, don't worry about losing some power in exchange for units that will get you hitting harder.Your first response from MisakiSakaki is solid.Juno must go. The boss is made to be immune to his electrocution. Mercury... Personally I have her tapping for now, mine isn't ignited.All attackers must be in the bottom row, especially if you're going to have Sytry's drive skill. Make her 3rd drive skill, it'll make the back row hit harder and increase the defense of the from row.If you have Ganisha at any level, bring her and make her 3rd drive skill.