General Gameplay notes:
Arlieth:
Load up training mode and practice 5B xx j.B. Getting this to land consistently will add so much damage to your game. You can't land it at all ranges but you can get a feel for when it works.
You have a good idea of how to abuse his whiff cancel strings. Try adding 2B 5A whiff 2B. And randomly from the ground using IAD B especially with snake backup, and using 2C as anti air when you have 421C setup to protect you.
Does the 5B come after 2B? As in, 2A 2B(1) 5B(1) xx j.B? The other version I've used reverses that order, where it's 5B 2B 2C xx j.B to minimize my combo penalty. I don't have frame data available to me, so I don't know if 5B has better proration or hitstun (though I do know it has better speed), but I remember in the past having some trouble consistently getting 5B xx j.B timing. Therefore, when I first started out, I switched to the 2AB(3/4)C xx j.A or j.C series for consistency's sake at the cost of damage, but I don't know how much it's costing me in potential.
I haven't seen the vid yet, but against Sacchin, I traditionally avoid throwing out too many pokes after whiff cancel because of her 2.C's priority over mine. I don't know if I had to vary my strings against AkaAkihas yet. Also, B.Snake can't hit Sacchin 2.C because it literally warps her hitbox past Nero's body when she attacks(1), so I've avoided that as a general rule against Sacchin unless she's already stuck in blockstun.
As for the 2C, you're absolutely right about that. That's the one move I keep forgetting to do, though I forget whether that's because I kept getting hit out of it by Shiki's j.C kick on his way down. Thanks for the input, I appreciate it.
PS: WTF were those 5Cs? I hate MB command interpretation.
(1): on the other hand, I've had an A.Snake going the wrong way because Sacchin crossed me up, and then she got caught by A.Snake when she hit past my body with the 2.C. Go figure.