Erron Black has two incredibly strong strings that end in double overhead attacks. These strings are his B222 and his 21212. He also has a Special Move called Rattle Snake Slide which hits low. A common tactic for Erron Black is to use the Rattle Snake Slide within his blockstrings to create overhead/low mixups which can be difficult to deal with. However, you can indeed fuzzy guard most, if not all, of these mixups with correct timing.
Fuzzy Guarding Erron Black’s B222
Fuzzy Guarding Erron Black’s 21212
The first mixup that can be fuzzy guarded is Erron Black’s B222 and B222 into Rattle Snake Slide, where the slide comes out before the last hit. The slide comes out 4 frames faster than the overhead, so in order to fuzzy guard this you must quickly block low then high.
Next is Erron Black’s 21212. The last two hits of this string can be mixed with Rattle Snake Slide. For the first mixup, the overhead comes out 5 frames faster than the slide. To fuzzy this, quickly block high then low.
As for the second mixup, the overhead comes out 8 frames faster than the slide. Again, quickly block high then low.
Essentially in order to fuzzy guard the entire 21212 string, you must block high, low, high, low.
The only mixup that is rather difficult to fuzzy guard is Erron Black’s B222 and B2 into Rattle Snake Slide. The overhead comes out only 2 frames faster than the slide. Unless you can fuzzy a 2 frame difference or react to the slide, then you must guess which way to block.
While it is useful to be able to fuzzy guard Erron Black, he can also use Scud Shot and Locked and Loaded cancels within his blockstrings, which can be difficult to react to if you are focused on fuzzy guarding.