General Strategy and Playstyle
Backdash alot against Hwoarang. His powerful moves need him to be up close, so
backdash and whiff punish when he misses his moves.
It is recommended to use a fast mid move like a shoulder to whiff punish as Hwoarang's strings
are generally fast and may interrupt your whiff punish.
If you are sure his string has ended or if he whiffs a big move (like b+3), then you can go for a big whiff
punish.
When he tries to close the gap on your backdashing, sidestep and block; his long range moves (like ff+4)
are linear
and his powercrush is -14 on block.
(d+3+4, 4) Rage Drive
One of Hwoarang's rage drives is a low-mid-mid string that is +7 on block and
leaves the opponent ins crouch and himself in RFF,
so Hwoarang effectively gets a free mixup.
Many players like to go for RFF b+2, which is a 16f mid punch that leaves him
+4 on block which allows him to continue pressure.
Characters who have a punch reversal/parry can parry this,
because the shortest punch reversal in the game is from 2-8 frames.
Keep in mind whether your character can parry while crouched; Leroy for example can't,
and has to cancel crouch with a sidestep into b+2.
d+3,4
Hwoarang's d+3,4 is a low-high that is a natural combo on hit and puts him in stance and plus frames for a
mixup.
While this is a good move, if the opponent doesn't know how to deal with it being blocked, it is as
dangerous as a hellsweep and can be ducked and launched.
A good opponent will react to his move being blocked and immediately go for the fast high moves or mid
powercrush in order to stop any punish attempts.
To counter this option, either use a fast ws move or a low that crushes highs. Some characters have very good moves
against d+3,4 (like Anna who has a launching low sweep from crouch), while some have at best their ws 11-frame punish.
For more details on d+3,4, see this video by LoseAgainMan (turn on subtitles), or this video by PeterYMao.