To be fair, no character is “difficult” to learn, it simply takes time. Once you practice setups, hit confirms etc. You’ll be able to put it all in a match. Know his footsie ranges, when to fireball, when to dp/anti air, and finally know the matchup. Once you get that untechable knockdown, all hell breaks loose and it becomes a major guessing game for the opponent, it’s just making sure your setups are safe, yet hard to guess.
Best block string(s) I usually use is c.lp, c.lp into c,mp knockdown - frame trap. Mix this in with tick throws and you’ll open the opponent up. Double c.mp into knockdown also works as a frametrap (Don’t do this in an akuma vs akuma matchup since he can punish the sweep). Try not to use low forward fireball as much as it’s not a true block string and you’ll get a lot of life = gone. Good safe setup is if you can hit confirm an ex fireball i.e. c.lk, c.lp, c.mp - ex fireball then heavy demon flip kick, if they reversal i,e, dp it will either depending on how early/late you do it, crossup and enables you to punish or will completly stuff out their move and enable you to continue your combo. Experiment - that’s the key.
What not to do: Fierce cancel into demon flip DON’T do that, easily walked under and fully punishable, or worse in Ryu’s case light uppercut ultra meterless. Whenever I mirror an akuma I sometimes see people do this and all i do is simply walk under and punish, my favorite one is sweep cancel into demon. People may also try to cancel their c.mp after a block string in order to create distance therefore you walk into a dive kick, simply light uppercut on reaction, but not too late otherwise it will probably whiff.
It took me around 2-3 weeks to solidify my Akuma play and around a month to learn framedata, matchups and what to do in certain situations. Overall around 2 months to master Akuma i’d say, although online is a bit harder since there’s the lagg and certain moves are harder to punish on reaction i.e. anti air may come out too late due to lagg and you get blownup, or tech throw may not register due to lagg, but when I play offline with my cousin I tend to have almost flawless inputs. I play on pad lol, may invest into buying a stick in order to do some OS’s.
The only thing left for me to do is learn some option selects although with a pad I struggle quite a bit on this, but oh well. - reaction for the wins.