hades Ⅱ statue%!!
Having 100%’d the achievements, I felt like I was pretty done with the game, but one little thing kept bugging me: the last of the three statues, which don’t have an achievement other than the feeling!
I’d managed the 24 Fear Overworld run component while playing through, but the 32 Fear Underworld was pretty darn Hard. After a bit of time off from the game I found myself doing a single 32 Fear Underworld run every few nights, noticing what was making it hard and what I felt like I could deal with, and then tonight after switching weapons and adjusting a crucial component of the Fear, voilà!!

I think the Fear is the bit that most needs “solving” to make this completeable (and to a much, much lesser extent, Arcana), so I’m linking them instead. Arcana and Fear — don’t look (or keep reading) if you wanna figure out what works for you on your own!
ROT-13 discussion of what I found key:
Evinyf Puebabf vf whfg zrffrq hc. Zl bgure nggrzcgf cerggl zhpu havirefnyyl raqrq va znxvat vg gb uvz — fbzrgvzrf yvzcvat ol gung cbvag — naq qlvat. V guvax V tbg gb uvf guveq sbez bapr, whfg oneryl. Ur trg naq uvf zvavbaf trg fb zhpu fgebatre. Znxvat gur qrpvfvba gb gnxr gur sbhe Srne uvg ol gheavat vg bss sbe uvz naq ohzcvat hc bgure guvatf jnf jung znqr Gur qvssrerapr. Nybat gur jnl V yrnearq gung lbh ernyyl qba’g jnag gb qb nalguvat gung erdhverf lbh gb fnpevsvpr be fxvc obbaf vs ng nyy cbffvoyr — lbh arrq gur QCF. V qvqa’g jnag gb srry ehfurq fb V tnir zlfrys n jubyr 9 zvahgrf cre ovbzr.
Gur bgure guvat jnf fjvgpuvat sebz zl orybirq Yvz naq Bebf (Negrzvf) gb Ltavhz (Fhcnl). V qvqa’g rira unir Fhcnl yriryyrq nyy gur jnl, ohg vg’f whfg irel fgebat nf vf, naq gur enatr (bapr V tbg hfrq gb erylvat ba vg) urycrq n ybg jvgu gur snfgre naq zber ahzrebhf sbrf. (V qvqa’g rira unir n Ehfu Obba va gur raq?! Yby jubbcf, fbeel Fhcnl.)
Gur xvg zrnag V bayl ybfg n yvsr bapr, qhevat Fplyyn be Preorehf (v sbetbe yby. ybbxf yvxr preorehf gub). Aba-eviny Puebabf jnf n jnyx va gur cnex nsgre rirelguvat gung yrq gb uvz!