If you're going to go with meaty use 2a or 2b. You can use 2c too, but 2a and 2b are the optimal normals to use here.
As for the timing, well you basically want any part of the normal to interupt them getting up, so that they have to wake up block. If they seem to be mashing 2a on wake up try whiffing a 2a and going right to j.2c for counter hit.
As for them doing heat or backdash on wake up, try double jumping over them and coming down with j.c to punish heat, or hold 5.C to clash with it. To get them backdashing, hold 5c to chase after them too.
Against ex hiero happy Ciels, use 2a for meaties when they have meter, so you can cancel straight into shield.