So after grinding some 300 odd matches over the past month, I think I’ve come to some very definite conclusions about the utility of shadow air-ORZ. Long story short, it doesn’t suck, and is actually an effective reset and conditioning tool. Its use is pretty particular though, so you definitely won’t be spamming it anytime you get meter.
I personally found that its best use is in the corner after wall splat situations, particularly against characters without DP’s. It’s basically a Hisako-specific reset to punish throw techs, backdashes, and jump outs by the opponent after you wall splat them. Any of these actions will result in an immediate recapture (with the grounded punishes also staggering) that gives you a nicely delayed manual opportunity to also bait a timing lockout. A good corner sequence of combo->wall splat->shadow air-ORZ can have an opponent eating 80% or more in very quick succession if they manage to get themselves locked out early.
Just as useful, eating that kind of damage also serves as a potent conditioning tool on your opponent, encouraging them to sit still and block high the next time you wall splat them. And this option is punishable by either a heavy influence or cr.MK->rekka reset.
Downsides to the shadow air-ORZ in the corner is that the blasted thing is -12 on block, so if you run into that rare individual who does nothing after wall splat you’re going to be eating a punish. For that reason, if you have full wrath after your wall splat, I recommend going into TK’d light air-ORZ instead - you get the same mixup (caveat that it might be backdashable, but this is an unlikely reaction in the corner), but can also do an influence tick grab if the opponent happens to block. As discussed previously, the damage differential between the two isn’t actually that different (shadow version adds some more PD I believe), so you won’t be missing out on much. The shadow air-ORZ reset is also obviously DP-able, though it does make some of the more angled DP’s actually whiff, allowing you to full punish as you land.
So there, that’s what I found out about shadow air-ORZ. It’s a good if situational move, and a good default option to use in the corner after wall splats. I didn’t personally find much utility in converting anti-airs into combos with it, but that’s probably more my own preference than anything else. But anyways, hope everyone can take this knowledge and go out there and have fun. And of course, if you think of any additional uses for Hisako’s least-used special, post it right here.