making the speed of the ball negative, depending on how its laid out, might not make the object go in reverse, and if it does then your going to end up with the controls reverse while its moving like that.
also the ball in zelda that was being batted around with the bug net actively tracked the player, it didnt just bounce back and forth at random, i didnt get into that before because first you need to worry about hit boxes and making sure that you can switch the object to go after the other guy at a specific time before you start getting it to chase you.
this is actually not as easy as you might think to accomplish, between the hit boxes and the conditions and what happens if you hit a wall and how do you switch which player and/or enemy the ball is chasing after this can both get pretty crazy very fast and when fully finished it can in its own right be its own game if done well.
thats why i would just focus on the pong tutorial for now what you want is to create a collision box around your player while the animation is playing and to create a step counter for the other guy each time they are hit, the pong bar is basicly a fancy collision box and once you can reverse the ball when it hits once of those then you can worry about tracking and then how to actually injure one another, but making sure you can get the ball to move the way you want it to is the most important part, then you can worry about the effects.