In Geras’ Infinite Warden variation, he gains access to Quick Sand, and in his New Era variation, he gains access to Sand Trap. Both of these are low-hitting Special Moves that can create mixups when used within Geras’ strings. When defending against Geras, it’s important to know how to fuzzy guard these mixups.
Geras can use 111 or 11 Quick Sand (or Sand Trap) for an overhead/low mixup. The last hit of 111 has a start-up of 21 frames. Quick Sand and Sand Trap both have a start-up of 17 frames, meaning that they will hit 4 frames earlier than the overhead. In order to fuzzy guard this, you must block low first, then block high.
Similarly, he can use 241 or 24 Quick Sand (or Sand Trap) for another overhead/low mixup. This mixup is easier to fuzzy guard because the last hit of 241 has a start-up of 23 frames. Quick Sand and Sand Trap will hit 6 frames earlier than the overhead. Again, you must block low and then high.
While you can fuzzy guard this, Geras might also stagger his 24 string if you are looking to fuzzy guard because it is only -4 on block.
It’s extremely important to be able to successfully fuzzy guard against Geras because the overhead in his 111 string leads into 1111+3 which becomes a Krushing Blow if only the third hit connects, and Quick Sand becomes a Krushing Blow if it has previously missed twice in a row. If you’re not confident in fuzzy guarding, another way to defend against Geras is to always block low and only block high on reaction to his overheads because the last hit of 111 and 241 are both 21 frames and 24 frames respectively, which are reactable.