As far as the speed, idk. I strongly believe that the view Void has in his ball is the actual position in space from which his attack will come, effectively skipping any distance in space and acting like a portal attack. You can see
here that his localized view of space is above the clouds, and Saitama, seeing his attacks come like twinkles in the sky, implies an incoming object, not an object that literally appears throughout all of space. We can see
here when God
approaches Garou that his movements are just weird clouds to everyone else. But those clouds are literally his feet portalling out of nowhere. This also means that if his ability is like Void's, God was walking on this Earth's bubble.