Frostheart
[10] Knight
Hmmm. All I got was 6K 3K, 3B after blocking it. Or just simply duck it with FC3k or 214A . I haven't fought many great Natsu's on Live so I can't form the best opinion. But usually, it all boils down to the 50-50. Either low or that low high cancel.
So even if I get hit out of 9K or so, I'm not gonna be discouraged from not using them. Unless us Yoshis have a sliver of health, a little i8 is not bad. It doesn't knockdown and it's probably our only best case scenario, however interrupting with 3K should be just fine. For both.
Gotta remember that if they go 4A+B6, PO K will TJ over FC 3K and 214A. PO A will hit before 9K (I have a habit on 9K-ing by instinct after blocking a bomb and more often than not it doesn't work out in my favor), and 6K whiffs if they delay/PO A+B/B+K. It is theoretically a somewhat 50:50, but IMO Natsu has better options off 4A+B6 on block than Yoshi. Plus you need to RCC a 3K, which I can't do instinctively. This coming from someone who uses both chars.
Personally, I just block and when they start getting adventurous and trying PO B, I try to guess and 9K beforehand. Or iMCF.