Thanks for the tip, 13F grinding ended up being the correct answer, quick, easy, and good EXP, leveled people up until I felt more comfortable, then I beat Yuyuko and Orin (Whom I had forgotten to kill), Great Stamp (Though it was a pretty hard battle) Kaguya's Foe (Whom decided to shenanigan me and back-to-back Flowing Hellfire, even though I had a full party) and finally, just now, Yukari.
Yukari went down after three tries, I took her first form as a means to buff everyone and debuff her, unfortunately, Reisen died pretty quickly, but after a lot of ATK Buffs from Ran and DEF Debuffs from both Orin and Iku, I sent in my heaviest nukers out to get her: Suwako and Nitori.
...Did they just deal 220k damage in a single turn? :getdown:
I was tempted to bring in Kaguya just for a second shot of Croaking Frog, which was dealing upwards to 150k damage, maaaaaaaan.
On the beggining of the fight, she got trigger-happy with Quadruple Border, but it was pretty easy after that, aside from when she decided to one-shot Mokou with Objective Border, not allowing me to further debuff her MAG.
Overall, a smooth battle, it was pretty easy, after all of the leveling, thanks guys.
Now, onto the teleporting madness of floor 17 and Rinnosuke on Floor 18, I've never been so close to the ending before :getdown:
(Reimu Level 75, btw.)
@EDIT
Got flan and did every single fight I can do at this point besides Rinnosuke, Reimu level 78, Wiki recommends 90+ for Rinnosuke.
I'm still grinding on floor 13, but the results are starting to slow down... I still can't reliably kill stuff on 16F and 17F/18F stink.
Help? :ohdear: