This is secretly an anti Nero thread in the Nero forum disguised as a helpful list for Nero!
Everyone (who has played against Nero) knows and loves 4c. But you have to be careful as you can't just completely spam it at will (or can you?). This is a list for people to contribute what Nero has to be careful of as he's pushing those buttons. Obviously if you shield, bara, or dodge it (either by being too close to Nero or command dodge) you can punish him but what this thread is concentrating on (hopefully) is what you can do after a blocked 4c.
Short Characters: (Only tested Ren, Miyako, and WRen)
These characters don't have to worry about crouch blocking 4c as the 2nd hit will always miss them.
Ren
Ground block:
TK EX Ice
A little hard but is quite doable, the closer you are the easier. Probably won't get the best amount of hits as you basically have to aim for his feet to hit him in time IMO.
Air block:
EX Ice
Obviously this is a bit easier than the ground version.
Special notes: Ren can catwalk under 4c.
Miyako:
Ground block
623c
Have to be really close to Nero but Miyako's fastest move is capable of catching Nero before he recovers.
236c
This isn't distance dependant at all since she always moves the same distance forward regardless of how close to Nero she is. Timing seems really tight though, might be forced to reversal just to hit Nero.
Air Block:
No options
WRen:
Ground block
623a
Can't be too far away but this is the punish of choice as it leads into combo into knockdown.
2b/5b
Won't really lead into anything but you can tag him with these. But why? Just use 623a.
214b
Needs to be pretty close, doesn't really lead into any better options than 623a.
Air Block:
No options.
Normal Characters (They have to block 4c crouching or the 2nd hit will hit them)
Satsuki:
Ground Block:
214a/c
Both work as long as you're close enough, which is actually pretty far. You probably only want to use 214a unless you're close to a corner. But if you really want/need that damage go ahead and use 214c.
Air Block:
No options.
Hisui:
Ground Block:
Arc Drive
Not a bad option, isn't very hard and leads to good damage. You just have to be in heat/max which isn't always going to be the case.
EX Dust
It comes out in 2? frames so it's definitely fast enough, but if you're close enough to use this and hit Nero, you're close enough for the 4c to miss in the first place? Might as well just do a normal combo.
Air Block:
236c
Needs to be so close you generally will never be in a position to punish with this, but it's possible. a/b versions don't seem to have enough range.
Tall class (Do Nero and Wara go here? Probably not, dunno yet.)