Been playing Asuka since season 1. This is a very good anti-Asuka guide! I do wanna add some more noteworthy tips as a barely intermediate Asuka main though. Apologies for the length, I have a lot to say about my homegirl.
Mainman already showed how Asuka is susceptible to SSR duck, is very linear, and basically wants you to press into her so she can punish. The result is that Asuka will slow the game down, and force situations where you try something risky only to get blown up for it. She wants you to become afraid to press, which turns the match into a game of small Tekken. This is a big part of why she can be exhausting to fight against. And she can sabaki electrics, so be mindful of that. When you force HER to open you up, that's when she'll start running her mid/low game.
Despite Asuka having good range on some of her key moves like DB+3. and she kept the buffed hitbox on D1+2, in my opinion she can still feel pretty stubby. If you're playing a real poking character, or someone with a weapon, you will definitely outpoke her and she can get snuffed by you if she tries to challenge. So Victor, Kuni, Yoshi, Alisa, all have some sort of range advantage and their weapon attacks can't be parried too. She will try to poke and fish with DF2 and DF1, but they can get beaten out. A good Asuka might try and read a whiff punish with F+2, but she's risking her life to do so since she's launch punishable if she lets it rip. She also has a bad backdash, and wants to be relatively close to you to get her offense started.
Mainman should have mentioned this, but apparently in the past Feng Wei was one of her worst matchups because remember, parries only work on punches and kicks. She and Jun cannot parry elbows, headbutts, shoulders, knees, and of course weapons.
Mainman also forgot to mention that a few of her moves can be canceled into full crouch. It's another gimmick to look out for on F+2, B+1, and three ring circus using the low ender.
When you implement SSR duck on Asuka, you force her to start using her less abusable tracking moves. F+4 is a high tracking kick that is +3 on block, but again weak to SSR duck if you duck in time of course. HOWEVER F, F+2, 1 is a hit confirmable mid heat engager that tracks to her weak side. It doesn't have a homing trail, but it CAN autocorrect so she has 1 option to cover her weak side because she's dashing toward you.
All in all, she will be annoying and tiring to fight against. But she can be overcome so long as you don't overextend and know where to duck and sidestep. Respect her active defense, and punish her for it if she tries it and whiffs. Hope this helps. If I'm wrong about anything please let me know! This is just my understanding from playing online ranked and watching pro matches.
I believe asukas strengths are her oki set ups. With her cancellable UB to numerous moves that hit grounded / launch tech rolls it is a nightmare trying to get back up against this character.
I believe trying to keep the fight standing and using backdash and ssr would make it matchup a bit easier
I never understood why so many people mention the long reversal window as a strength. you're just givng more time to your opponent to hopkick launch you.
About the b4,2,3 string while yes last hit WAS delayable in 7. Now you can only delay the second hit and have to fully commit on the third hit now. Or it has a super short delay now, it's the reason i rarely use the third hit.