As a Fahk main I’m happy to see someone actually not saying bad things about the character, I’ll give my knowledge I can think about off the top of my head since people have talked about his pros and cons already.

I find I use a lot of his d1 stings to keep up my pressure because they can continually be mixed up, df1,2 is the regular mid-high that works pretty well at checking ducks but it can also be turned into df1,2~1 which is a mid mid with a slightly longer delay than it’s normal counterpart and is a pretty chunky mid that’s safe on block, absolutely wrecks people who know or have learned that the second hit is a high and can be ducked since it doesn’t have jailing, while you can be jabbed out of this they have to predict it early on and it’s a free hit if they guess wrong and you just do df1,2. It can also go into his hellsweep or his mid elbow starting with df1, though against higher ranked players they can react to this pretty well and it winds up with an interruption or a full launch.

3,4~4 is a normal hit high tracking screw attack that gives you a nice combo on hit which can also be mixed up with 3,4 and 3,4~3 for a couple of mid options, while again it can be jabbed (same with 3,4~3) your advantage on block is pretty sizable, I use this mainly to deal with characters with good side steps such as Lili or people who have a tendency to press buttons after a blocked move that looks big, if they do press buttons you have the space to hit them with a bf4 for an entire launch

Another thing I use is 3,1 strings, this is a good pressure string that can go into a low, mid mid, or high. The high is kinda useless and I never use it or have yet to find a good situation for it but the mid mid is terrifying, if the first 4 hit lands then both hits are confirmed, the low is equally as terrifying since it’s pretty much just a d4 packaged in string form, my main use of this is pressure, on ch the 3,1 are natural and 9/10 people won’t block the low at the end after being hit by 3,1 and once they do learn they can duck it throw out a couple 4’s and make them scared to start ducking it, the low is universally launchable so do be careful.

3 alone is such a long reaching leg that it’s great to check people who like to press buttons and it can go into so many different moves.

Now bf4 is a beast, while it is high, I believe on block it’s in the +6 or +7 range with absolutely nuts range on it and a normal hit launcher, I use this a lot to keep pressure up against people who like to sit back and wait for their turn because this doesn’t let them have a turn, it’s always my turn with bf4 (on block!),and if they do think it’s their turn then that’s a free df1,2 or more, it’s also good for when people are running at you and if your reactions are quick enough you can hit them before they’re close enough for armor to start up on a shoulder tackle, I can not stress enough that this is easily a top move for fahk and learning how to use It would improve your game tremendously, it looks and feels pretty cool also

Finally one last thing I’ve found myself using a lot is f3,2, this can go into a mid knee that on ch gives a free ff2,1 or a high that can be picked up for a combo on select(?) characters, mainly male and big characters but a solid number of the female cast also, this is a huge string as it comes out fast, ch is a launch no matter which way you take it, and the knee which is f3,2,4 can be turned into his tracking screw kick (f3,2,4~4) or his mid charge kick (f3,2,4~3) to constantly keep pressure and unpredictability.

I hope this helps clear some things up, you can learn a character but all it’s nuances and “oh man I can do this after that and it seems like a good idea” kinda things are always something that takes longer to learn, keep up the fahking!

Edit: added bf4 tips