Hey there, here is some conditioning advice that may help you up a bit:
1- Practice your dagger cancels every time you can, skarlet can't trade at all against everyone in the cast, but she can cancel the rest of the animations by D3 imediatly after she cancels a regular dagger.
2- learn do iaD, is important, even if you don't get to hit consitently, making the 1st one consistently is a pretty big deal, is +25 on hit.
3- Conditioning your muscle memory to be in sync with your eyes reaction, this will help you to condition yourself to not downslash or upslash after a ex dash, specially when they bait it for you do ex dash into upslash or downslash, knowing how fast or cancelable a move can recover from also helps.
I normally take other options to not fall for the temptation, which is empty dash into F4 pressure/punish, or 114, or yet f212,1+2 blockstring when they expect a downslash.
KL has a very tiny hitbox, his aproach must be very carefully and you need a good spacing and a very high fast reaction skills to punish his actions on reaction, like teleport low hat and 24,1+2 or 24,lowhat.
You can duck under teleports and uppercut it, it helps a lot, in case he uses with meter, you need to know where he will come out later, the KL teleport is tricky, without meter he will always getting out behind you facing the place where he took off.
With meter, he will always come out where he left, which means he will be in the same position, only near your for a full punish, if you notice this quickly you can step away correctly from the teleport, he can grab early to have armor and start stringing with it, be careful with this..
Kung Lao has a F3 that brings him up, avoiding even iaDs, be sure to keep those in check.
His D3 is 9 frames, and not 7, take advantage of that, bait spins by faking that you're committed to the rushdown game.