DO NOT get nair confused with Dair. Dair cancels into everything but it has so little hitstun its useless. You can do this weird ffdair-anything link but again, the lack of hitstun will cause you to just get hit out of it
Just going back and forth fast isn't really Dash Dancing. Proper DDing is when you dash and return the stick to neutral before they start actually running. Basically constantly and consistently doing the Dash starup animation in either direction. When you do this there's no turnaround lag and...
Aside from all that growing up watching and playing pokemon I never found mewtwo to be that cool
I will say, Itd be cool to have a psychic, grappling mewtwo