Why are Rock Leone's attacks made of air, not rock?

in 4d he did use air + rock + sand + i don't remember

cuz kyoya says hes the master of tornato...i guess thats y...

I guess the name rock leone is just used for it to tell that the bey is tough and that it further puts meaning that it is a defensive type. You always hear them say as tough of a rock. Plus he wants to master of wind and tornado.