I've played this MU recently (FA vs duelist/flame fist) with
@xQUANTUMx offline. It's not the most fun thing in the world, that's for sure. Here is where I had my success:
- Jump range, weaving in and out throwing out some low rockets to challenge, trying to bait a jump and go for an up rocket. Making a read on fireballs and trying to jump in (which isn't easy because LK has a strong d2 and can use b2 to trip guard well). and if I can get him to respect the jump range by using her projectiles, then go for some run up pressure.
- Counter poking, Since we are mostly blocking low vs LK, we end up blocking a lot of pokes. I like to counter poke with 1212, like after a blocked D3 because 1212 is suuuuper hit confirmable. Counter poking LK's D3 reminds me a bit of MK9 style counter poking, you have to be really quick with it. Once the LK learns to respect the 1212 post poke game, he can either poke again or go with his fast jab (which we can d1) or he'll just block. If he's just blocking the follow up go into a 50/50 or 1212-guns which jails, builds good meter and is safe. Don't be afraid to counter poke with a grab also, it put's you back at that jump range where you can press your advantage a bit with guns, jump reads and low rocket. It's not fool proof obviously and LK has answers for everything we do.
- Whiff punishing, whiff punishing with Jacqui is important and strong with her walk speed, but isn't the easiest because of her somewhat slow and not super far reaching F1. I find that most of my good whiff punishes are more set up for whiff punishing. Like if we are in a situation where I am slightly + (like 1,1) or a situation where my opponent might be expecting a string into a special (1,2,1,2- guns) i'll just go through the string, not cancel into the special, walk back and immediately f12 and hit confirm. Because of Jacqui's great walk speed we often make pokes or even normals (Like LKs common low string) whiff, and since we've already inputted the f12, we could either get a punish, or back to neutral.
- Trust your reads and know your punishes, If you read that he's going to do the parry post bike punch thing, trust the read and punish with b33. I know it sounds easier said than done, But it's just another thing in the MU that you'll need to do to win. Some of LK's stuff whiffs, i don't know when and I don't know why. But learn it and punish accordingly.
I agree that this MU is difficult (from the experience I've had so far), so hopefully these things above help.