Perhaps a long shot, but does anyone happen to have a list of the characters that are forced to block both hits of Akuma's s.hk on block?
That's super helpful! Thanks!
If your talking about his s.hk where he moves forward, I know a little about it, mostly what Blanka can do. I tested his options against this move when ultra came out. It's actually one of the reasons I use Ultra W for this matchup.
There is a 8 frame gap between the 2 active frames of each kick, blocking the first hit it is less due to the block stun, while I do not know the exact block stun frames, this is where the spacing of the move can make a minor difference. When blocked deep or very close, the move is very unsafe on blocking both hits, however, it has slightly least time to reversal in between kicks. The timing is very tight, but invincible moves on startup, 1 Frame throws(ex. Zangief's Ultra 1 and Super) can beat it. I honestly do not know if 3 frame reversals will beat it. Further out is safer on block after 2 hits, but is a little more open to reversals in between kicks, all the above moves can still work, (command throws can be iffy due to spacing/which version is used) and a few more reversal options are available, I believe some armored moves can work here, although the timing is still very tight. Which ones work I do not know off hand.
When I said I use Ultra W for this matchup, there are reasons, mostly overall utility. Most Blanka's will go Ultra 2 in this matchup however because that's what you normally use against shoto's. Akuma's tend to use this move up close vs. Blanka, as he has a hard time dealing with it. If he blocks it standing, he cant charge EX Up Ball in time, and any regular ball, even EX, are not fast enough to come out in between. On blocking both hits, Blanka really can't punish, not at all if spaced right. However, the first hit tends to hit on block when crouching, but will whiff on the second kick, in this case, or if the first kick whiffs, Blanka can get a free Ultra 1 punish. It can also punish poorly spaced sweeps, which Ultra 2 cannot punish regardless of spacing, and whiffed tatsu's.
Edit: While not that useful, and you will probably never see it, a preemptive coward crouch will cause this move to whiff entirely, and that move is special and super cancellable. I should really make a post about what kind of stuff Blanka can do with coward crouch, it has some absurd low profile capabilities.
Sorry for the late reply, while not the exact answer you were looking for, I hope it is at least helpful in some way.