Yoyos can be used as weapons but they'll practically be just like small flails on a string.
Here is the battle scene that takes place in Japans leading random pipe storage facility.
Pipes, feet, and mean looks are all more effective weapons.
Alright listen,i love yo-yo's and hot chicks fighting each other (who doesn't?) But,c'mon this movie looks so unrealistic and just.... Well,BAD.
But then again,it's just my opinion.