When going into the mirror that takes you to the room with the pillars, you can do a thunder on the stairs to hit some of jars around the mirror to get some extra hits in. Also, hits from the Aqua 2 fight carry over after the fight so that helps with building up the arrows as well. You can also get 3 hits in on Aqua 3 at the very start of the fight where she transforms into spellweaver. Hope that helps!