Ruling Mega Gengar's Phantom Gate from the Discard?

[Lord Goomy]

So, I was thinking about the card text on Mega Gengar EX (PHF-35) and came to a strange conclusion:
The card says:

(P)(C)(C) Phantom Gate
Choose 1 of your opponent's Pokémon's attacks and use it as this attack.

Think of this:
The attack doesn't say it has to be in play, it just has to be one of your opponent's Pokémon, so it can be in the discard pile and you can still Phantom Gate for its attack, right?
Please help!

 

[biffthepotato]

I don't think so but good point you should look up the rules for that

 

[MultX]

Pretty sure you can't. They write for discard pile specifically, it that's the case.

 

[PMJ]

You can't copy anything from the discard pile unless the card specifically says you can. Nice try.

 

[Lord Goomy]

Alrighty then. Problem Solved!
I thought I had a loophole there. Oh how I love loopholes...