Try using limits, summons, and drives where you can without a whole lot of consequence. Be sure to stock up on items and use the best equipment open to you. Of course, leveling up helps a lot too. Take out every challenge in the matches as quickly and clean as possible, taking out groups of enemies at once will really help (IE - use Magnet/era/ega to draw in enemies and deal damage and then, take them out with a few simple hits. Let me know if you need to know anything else.