Not exactly the matchup thread, and not exactly a simple question, but okay:
Neutral jump is not a good idea. If Blanka has good reactions he can simply swat you out of the sky with up ball. If Blanka hits you with the very tip of his fingers, then his slide is safe. Any closer then it’s punishable by cr.HK. Closer than that and it’s punishable with st.MK. It has slow startup, so if you suspect a slide you can counterhit it with your own slide and then link (either f+LK or st.MK) into a combo. It also has slow recovery, so it is easily whiff punishable. Max range slide may be an unpunishable poke, but constant movement from Ibuki should make it very difficult to space correctly.
Actually level 1 focus won’t punish it unless you counterhit it (kind of hard to do). Level 2 focus is the better option for the crumple, but this really isn’t necessary given the above options. In this match you’ll most likely find yourself using FA to punish Blanka’s slow pokes, such as cr.HP, after you’ve trained him not to do random horizontal rolls of course.
Only point blank MP/HP horizontal rolls are punishable with ultra 2. If any of his rolls aren’t point blank, then it isn’t punishable with ultra 2. Punishing with ultra 2 requires very good timing anyways. When in doubt, just use hp neckbreaker.
If you get hit with an EX horizontal roll, you can catch him by surprise and dash up and kara throw. If you get hit by any roll for that matter, you can dash up and put pressure on him (without frame advantage though).
For okizeme I highly recommend you learn a neckbreaker safe jump, whether it be the one Izuna listed or a safe jump involving j.HP (such as: neckbreaker , whiff cr.MK , j.HP). Blanka’s ex up roll is 4f so practice well. But even if you get hit with ex up roll, as long as your timing wasn’t way off (within about 4 frames, such that you are grounded when you get hit), it’ll be the same situation as if you got hit point blank with an ex up ball, so you can still dash up and kara throw or do whatever.
After you master that, you should also master your vortex timing. In this matchup you don’t necessarily need to go crazy with vortex setups, as you only need one or two setups that look like or is kunai vortex. One such setup you can do is super Ibuki standard vortex timing, which in AE translate to almost never crossup kunai. This way, since you’re not crossing up but yet still landing on the other side, his EX up roll will whiff completely. An even easier setup, is to simply take a short step back after neckbreaker and then SJ kunai. Due to timing this will almost never cross up, yet it puts you in perfect position and timing to do safe jump sj.LK instead, in case you need to safe jump his U2. It won’t be safe against EX up roll, but you should be baiting his EX up rolls with the other setups anyways. If you manage to bait out his ultra 2 this way, you can probably end the round right there.
While this 50/50 is generally in Ibuki’s favor, in case you don’t want to take any risks, you can always fall back on your trusty safe jump setup.
If you want a braindead safe jump setup, use:
EX neckbreaker , lk.cd , j.HP
easier than the regular neckbreaker setup because lk.cd is a special, and thus bufferable, or having a larger input window.
When vortexing Blanka, if you throw the kunai, you may have to watch for his FA dash since it’s pretty quick. Also, if he mashes backdash, he’ll be put into a juggle state, similar to vortexing super Ryu when he mashes jab dp. When this happens, you can juggle with raida, kazegiri, cl.st.HK, whatever you want.
If you manage to hit Blanka with a meaty kunai, your best damage combo would be TC4 , st.LP , st.MK xx special. If in doubt if the kunai was meaty or not, the next best thing would be st.MP , st.MP , st.MK xx special. If you want to use crouching normals, keep in mind that you can only do up to 2 lights before he’s out of range for a 3rd light. For example, cr.LP x3 whiffs, so you have to do something like cr.LP cr.LP st.MK. Also keep in mind that due to Blanka’s retarded hitbox, far.st.LP and st.MP will often whiff on crouch, and when he’s in hit reelback. For example, try doing noncrossup kunai and then combo st.MP. It’ll never work beacuse Blanka’s hitbox is the most retarded hitbox in the game next to Chun.
Actually for this matchup, I would advise to ditch the TC4 habit, since st.MP st.MP st.MK will work almost all the time (make sure you cross to the other side, so you can st.MP the back of Blanka’s head) whether he crouches or not. Unless in special situations where you know what you are doing and you don’t have to worry about a crouching Blanka, such as when doing cl.st.HK mixups and then you do meaty cl.st.LP. In this case, using TC4 can be better since you can hitconfirm into another reset or blockstring or whatnot.
To deal with mash electricity, when in doubt, simply use f+LK. It will beat it every time unless you are point blank (in which case you’ll either get hit or be put in blockstun), unless it is EX electricity. If you are farther away you can use st.MK or cr.HK, but most good Blankas will not mash when you are this far anyways.
Switching over to Blanka’s pressure game: it’s very weak imo, compared to Ibuki’s. It’s basically hop trickery that we’ve seen since vanilla, with some small buffs on his lights and electricity blockstun, I believe. Going by theoryfighter, I do not believe Blanka can option select Ibuki’s backdash, except maybe with his df.HP slide, but then this means he has to pressure you without back charge, which means no combos into roll. Though I don’t play Blanka so I may be wrong.
Patience, good cr.MP usage and midrange control, and mastery of Ibuki’s okizeme will pretty much secure you the matchup.
at least 5.5 - 4.5 Ibuki favored imo.
Did I miss anything?