I feel like a fair few people have the wrong idea about this variation, that it is some defensive careful safe-play attrition/Iceball-spammer. I'm not saying that it can't be this, but in no way is this a role he is locked into with this kit I play Sub aggressively as possible, I play the most rush down sub I've encountered yet and I use this version, and not "just because" either
A simple explanation of my game, I basically just spam the 50/50, both have excellent wall carry, no meter. Anytime I connect an Iceball I generally end the string in a F12 for hard knockdown, so I have time to use Ice Aura and still run up in their grill and be threatening a 50/50 by the time they get up.
Why do I use Unbreakable? Because, the Ice Aura is massive. I always Ex unless I have them in the corner. I've seen the logic used "but you don't want to be taking hits to begin with so spending a bar here is like playing with the intention to lose". Well, actually that's not bad logic (depending on how you play). However, the way I play, I don't quite think it is as accurate. A 50/50 is exactly that, a 50/50. And the times that it gets blocked, well the B2 is really easy to punish really heavily. The B33 is harder since you can hit confirm, and then on block Ice Parry a punish. But I do get blocked and punished, caught out, wake-up'd, teleported on and don't react fast enough, get breakered and lose the neutral game, or just make a mistake and press the wrong buttons (*shakes fist angrily towards beer*), whatever else, and assuming I have Ice Aura up and Ex'd for every hit, it basically means I have a health pool of 150% every other character. And I DO nearly always have Ex Ice Aura up when I'm being hit, lots of games it's been up for every single hit I took - rushdown builds meter fast, and casting it after ending a string with a hard knockdown (never in the middle of combo during Iceball freeze, ALWAYS outside of combo for max duration if I'm Ex'ing it), means it's up when I'm getting attacked.
And what else am I going to use the meter on? Midscreen the only other real way to use it is to extend B2 with Ex Iceball, which gives like 8% damage and a lot more wall carry for 1 meter, which admittedly is probably pretty decent for the carry alone, but I find this chain seriously hard to land playing in real life, and not even feasible for me online at this stage, but maybe I just need to level up here, I might practice it a bit more. Wake ups, we have no Smash, and while Slide is good I try to use it sparingly or it becomes an easy punish, I'd rather try my luck at blocking, especially if Aura is still up or just back dashing, and saving the slide for a surprise corner reversal. But all that aside, at the end of the day, at the speed I try to play at, if I've wasted meter on Ex Ice Aura it's a GOOD thing because it means I'm winning anyway. No Chip damage is just a bonus.
Ice Parry is no slouch for my game either, it's excellent for aggressive Sub play because with good prediction Parry can not just save me from a ton of wake ups both Midscreen and corner, but also give me an EZ combo set up too. Also, on a blocked B33, there is a lot of punishes you can Parry if you cancel into it, but it's definitely a prediction game here because it's -40 if they don't (although the animation is a little extended and does disguise a bit of that which can help). I try to pay attention to my opponents wake up patterns and get reads before I start using Parry though, I don't mind eating a couple of wake ups to learn this, especially with Ex Aura up, and eating a wake-up is generally preferable to eating a full combo that whiffed Parry gives them. But most of all it's just an excellent way to control tempo, no-one can out aggression you or rush you down because of the threat of it alone,
@Sharpyu posted an excellent video of Goro having a very bad day in another thread. Land a couple of these and your opponent HAS to respect it or lose, so just the threat of it being there let's you be more aggressive.
Grandmaster obviously has a strong(er) corner game, but I'm happy with using Parry predicts as pseudo-Clones to play around the lack of them, and it actually blocks a lot more things. Keep an eye on their meter, with perfect prediction I think it's actually stronger, although if you whiff one it will hurt, so you have to be cautious meaning some wake ups WILL get through - or maybe I just need to work on my reads lol.
Cryomancer is the one everyone is sayings the "Rushdown SubZero variation", but I just don't see it. I mean sure, that's the way to play him, and the strings do a little bit more damage midscreen, but not as much as other characters. He's basically a slower Reptile, with weaker strings and Iceball instead of a character trait or Slowballs (both better tool for aggression than anything Cryomancer has). Hooray. No, to me Unbreakable is my rushdown SZ, Cryomancer just seems pointless, which disappoints me because as you might imagine, he was the one I was most excited for (and aesthetically is the coolest too IMO).
Hope none of this comes off at all pretentious, just sharing my views on a variation that seems to have gone under the radar because it seems to have been a little unintuitive and met with mixed / confused response.
TL;DR: Basically, if you play as fast and aggressive as you can and Ex Ice Aura basically means you can have 150% health pool, which in turn means 150% time spent beating ass!