This glitch is a very old trick and allows you to fight without taking damage. The way it works is when you see an enemy about to fire a ki blast your go in to the flying animation. When you get hit( you also take damage so make sure you have enought health) you will revert back to walking but the game thinks your flying. So because of this you can punch enemies and no risk! Now you see the video raditz is being punched at certain times. This is critical as there are invisible Iframe(invincibility) that the enemy cannot take any more damage. According to a TAS(tool assisted speedrun) video bosses get .70 seconds of Iframes so you can hit every second to get the max damage on someone.