The battle against Chi You (the eight-armed demon in Gate of Illusion) was hilarious. First, his weapons aren't anything to write home about - his huge axe projectiles and shuriken won't even hit you as long as you're at ground level. The real threat is plain old collision damage, as his movements are mostly random and he's totally immune to projectiles so you have to get in close and personal with your whip. And he likes to block things with his shield. But it turns out that if you whip his shield several times it'll stun him and create a short opening where you can jump and leap up to strike him in the face - but then he counters by hopping forward into you. Anyway, I did beat him after about six tries ... only for part of the ceiling to fall on me when I tried to go for the treasure chest. Kaizo Trap much?
WTF Viy is immune to subweapons too? Okay, at least I can get in striking range with my double-jump, but that battle took a lot of tries (didn't feel like as many as Bahamut did, but still) mainly because Viy likes to spam his IMA CHARGIN' MA LAZER attack a lot more than he used to (and more or less from the start of battle), and how it burns off some of the platforms makes it much more difficult to hit his eye when it's exposed. On the bright side, he only advances when his eye is open instead of all the time.
At least climbing the Tower of the Goddess wasn't quite so annoying. Those invisible enemies now act like Boos from the Mario series - they back off when you're looking at them, but charge at you when you turn your back. Fortunately they have a very slightly visible silhouette now so once you know where they are you can take them out. I need to do something about those Goddess statues though - need to find a way into the Chamber of Birth. Seems like I need to save up $200 for that snapshot program in the Tower of Ruin shop now.