Uh... for damage I've been going with Nitori, Suwako, Suika, Yuugi, Patchy, and Marisa. The thing is they all freaking die in the first form, and of course it's REALLY hard to pull them out there because then a Start of Heavenly Demise will come out of nowhere and fuck me over. For tanks I've used Meiling and Tenshi, but then I scraped Tenshi for Komachi. Not sure if that's the best plan. I also have Reimu for defensive buffs, Minoriko for healing (though I assume she's useless), Iku and Ran for buffing... and that's pretty much it. It's the best party I honestly have. Of course, I don't think being at Reimu 92 is enough, huh?
Also, he's NOT weak, Zil. How long was it since you last fought him?