Tyranitar and Alakazam

[senior pokeboy]

If my opponent uses an Poke-Power, and i have an Alakazam and Tyranitar in play. Can i then choose to use Alakazam's Power (discarding 1 energy) before Tyranitar's Body? I would say i could when Tyranitar says AFTER your opponent's Pokemon uses a Poke-Power. But i'm not sure in that comination.

 

[PokePop]

You would have to use Alakazam's Power first or not at all.
Since Alakazam's Power would be used to block the effects of your opponent's Power, you can't wait until they have finished using it to declare it.

So, your opponent would declare their Poke-Power.
You would declare Alakazam's Poke-Power before they have actually used theirs.
Then, since their power "counts as having been used", you still get to use Tyranitar's Poke-Body!