I've used 6C after 6A or 4C on occasions when they CH, if only to bait FC (since people are mashing normals to break out of stagger, it works), if they tech it without doing anything and block it, that's one less Guard Primer, anyway (unless they DP out, which I'm wary of). Also seems to work sometimes after 3C CH as oki. Not saying it's surefire or anything, I'm just saying these methods have worked for me. I'm usually agressive with Haku (probably my habits from using Ragna), so they expect me to swing around fast normals a lot. I don't use 6C mid-screen so often as I use it when they're cornered and expecting a 4C, 5C, or 2C. The main thing is, stagger (4C CH/6A)>6C works sometimes if they mash out wrong.