If you want to boost your total power the fast way is to give manyus to the lowest level girl on your team. It's not very good for getting stronger though, one good team can make it a lot farther than a lot of weak teams. I leveled my girls evenly and they crashed like waves against the threestepper nodes in 12-5 until I focused on one good squad. Now I have a squad that can beat the map on its own most of the time and it doesn't matter what I have in the others.