So yeah was doing his arcade mode. Picked up on his grab confirm pretty fast (from seeing mostly every Raiden do it online). Just takes a few times to get down and then it's pretty much easy. Did it about 10x throughout the arcade mode.
His backflip sword AP Burst is even easier. It is the only AP Burst that I have found to be possible using only one move...besides Isaac's gun loop, and Nathan and the Cole's 3-hit punches if they catch you into a crumple/butt-drop every time.
As an anti-air, just aU2, (reversed) aU2, (reversed) aU2, (reversed) aU2, (reversed) aU2, ad infinitum lol. It's laughably easy to do. -_-"
Well okay, I'll stay on topic. It's pretty much easy to connect U1 to an aU2 if you simply input a diagonal directional input instead of turning around mid-air. You can then go for the kill confirm or just loop into aU2 forever. -_-"
Tbh it probably was hard for them to get used to. I remember I couldn't do it for a couple of days the first time I tried it. Then when I finally did do it, I couldn't land it consistently until a couple days later. So i'm sure others had similar problems as well.