They're two different shots. As far as how they're shown:
Originally Posted by kokusaikone
Cyclone Smash - Rikkai Arc v. Sanada
Cool Drive - Higa Arc v. Tanishi
Cool Drive - Rikkai Arc v. Sanada
Cyclone Smash - Not shown in the manga
Cool Drive - A smash that doesn't bounce.
Cyclone Smash - Echizen jumps with his body twisted 90 degrees and he snaps it back to normal position as he hits the shot.
I hope that helped you. ^_^
tannhauser should be unreturnable i think... a serve must hit the ground first before you can hit it back... but how can you hit an unbounce serve ??
Originally Posted by Sylent_Viper
Tannhauser was returned by Atobe when Ryoma copied it with SoSA with the Front Foot Hop.