KONATA DOWN!
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I started the battle with a Scroll of the Gods, and used 3 Superior Mana Draughts (which could have probably been Averages since I ended with half MP, but I came as prepared as I could be), a godly Spirit Draught, an Infusion of Gaea, and a second Scroll of the Gods when the first spark expired, just in case Petanko Smash crit (which I just realized was a waste, since Weaken prevents physical attacks from critting).
I kept Weaken, Bewilder, and Poison up at all times. Poison was dealing 110+ per tick when applied during PA. My spirit attacks dealt ~6000 with PA up, out of her ~35000 HP. The Infusion of Gaea was awesome. It doubled my damage for 50 turns, since Konata is weak to soul. Sadly, without PA up that was still just 40 damage per attack, so I don't think using a Gaea infusion is equivalent to having an ethereal weapon.
Petanko Smash was hitting me for 820ish damage, but my 1412 HP easily took care of that (and she only used it 4 times, 1 of which missed). Timotei was hitting for ~350 since I had her Bewildered.
Time to try for Mikuru!EDIT: MIKURU DOWN!
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OMG that was a crapload harder than Konata. I had to blow all of my 3x Scroll of the Gods, 3x Mana Elixir, and 3x Spirit Elixir, and I killed her with only 6 mana and 500 HP left. Thank god 2 of her 3 Time Quakes missed, and she sat at 100% spirit for like 20 turns before her death (the one that got me hit for ~1000).
I also made a huge blunder right at the start. After using my first Mana Elixir, I was also ready to use a Spirit Elixir to recharge my Spirit Attack. Unfortunately, I accidentally double-clicked a Mana Elixir instead... while my first one's buff was still active! Considering how close I was to death at the end there, that would have been the difference between success and failure, if I'd had a little worse luck with Time Quakes.
Anyway, it's time to move on to Ryouko, but I'm concerned. I don't have an ethereal weapon, so I won't be able to deal noticeable damage to her with melee attacks, right?
What should I do to prepare to fight Ryouko?