the following scenario is pretty common now, so nothing to hide...my old defense was based on this idea and it was doing pretty well...visions can steal energy pretty often and in addition to this he can strip toons.
if he goes first like he does most of the times and steal energy which he does pretty regulary astra can use her powermove immidiatly on the first turn on a somewhat stripped defense. you can force her doing that even more and even better....this is just a stupid broken move. yeah there are ways to counter it to some degree, but nontheless..
in many cases you have your team left with all possible debuffs and without a lot of energy so it's almost impossible to recover (perfect corruption is really badass).
this scenario itself sholdn't be possible because it's simply too much...this alone makes it necessary to increase the powercost at least to 6 but better to 7 points. you will see many defenses that rely on this, right now (my new def too for example). in addition to all other arguments brought up from several players should make the decision pretty clear...