I like his down b but it seems that it isn't all that useful or that interesting, what if you can summon the full size sand storm and change the specials and make garchomp more floaty in the sand

Sand storm special ideas:
Neutral special: a stronger projectile that can be angled in sandstorm

Side B: a glide that can be canceled on hit with an aerial and by pressing shield you go into special fall

Up b: Can be angled

this is just ides, you don't have to add them but it be nice if sandstorm had a bigger role in the move set