Just FYI Ivy
Demonstration of Ivy's Summon Suffering being GI'd and RE'd. It can't be blocked but it's not an unblockable-attack. It can't be throw-broken but because it's not an unblockable attack you can GI/RE it like a normal throw. Also can crouch under it, back step out of range, tech crouch, hop over it, or whatever. Whether it's the normal version or just-frame version doesn't matter. It's a normal throw despite the flame/fire spark and woosh sound affect on startup -- the only difference is that you can't throw-break it.
In other words: It has all the same properties that every throw has, and none of the same properties that any unblockable-attack has.
If you call Ivy's Calamity Symphony a command throw then you should also call her Summon Suffering a command throw, not an unblockable.
Why does it matter? Why is it important? Imagine if it was actually an unblockable, Ivy would get a guaranteed Summon Suffering for every time she does a Guard Impact. After Ivy does a Guard Impact you can't do anything except reverse-GI or RE, and those two things lose to unblockables -- fortunately Summon Suffering is NOT an unblockable so if Ivy does get a GI you have a way to beat Summon Suffering by using reverse-GI or RE. If it was an unblockable attack then it'd be guaranteed for Ivy.
For those that think that Ivy should get a guaranteed SS off GI: you are wrong. No one else gets guaranteed anything off GI, it's a mixup. Ivy continues to get nerfed every patch because the majority of the player base believes she's overpowered. If she had an actual unblockable-SS everyone would freak out and for good reason, it would be so broken compared to what anyone else has.
LIke please just stop calling it an unblockable. It's a command throw just like her other command throw.
The last clip shows Taki's PO stance~step~UB~cancel thing.
It's just 214 8 41236B G
You have to input the command for the unblockable (half circle) very soon into the step. So it's slow, but the input is very fast. Like, you don't want to wait for the end of the step to start the UB, you want it to cancel the step early on. I'd actually hate it if they patched this Taki stance cancel out, they should just leave it in IMO.