Oooh, so Izayoi could possibly have stance cancel shenanigans like Johnny's Mist Cancels? That sounds awesome! So if I'm calculating these right, the numbers on block should look something like this, assuming that you can cancel after the first active frame:
5A: 11F blockstun - 10F cancel = +1
2A: +1
5B: 13F blockstun - 10F cancel = +3
2B: +3
5C: 16F blockstun - 10F cancel = +6
5C(GA): +6
2C: +6
3C: +6
2C(GA): 18F blockstun - 10F cancel = +8
6C: +8
Please correct my numbers if they're off!