Shadó Chimera / シャドーキメラ
Smash Ace
Yes that's called wave bounce. You can also use the C stick if it's set to tilts which will let you use it on the ground.That results in a B Reverse. If I'm running and jump right, press B, and hammer left, I'll face (and move) left and fire left.
I want to be running and jump right, do the correct input so that I face right, move left, face right, and fire right. I believe this is called a Wave Bounce. I'd find a video if I weren't at work... I'll see what I can dig up later.
Non C stick method:
Moving right in the air, hit left, do neutral B, hit right.
Tilt stick method:
Hold right, C stick left + B (same frame)