Complex sentence: The meter slowly empties when an ability is in use; once it depletes, Viewtiful Joe reverts back to normal Joe, leaving him temporarily devoid of VFX Power and lowers his attack and defense.
Split into simpler sentences: The meter slowly empties when an ability is in use. Once it depletes, Viewtiful Joe reverts back to normal Joe, leaving him temporarily devoid of VFX Power and lowers his attack and defense.