Delta Blast

[PokeMontoya]

HI ATM! Question about Slamance d Delta Blast Attack.

http://pokegym.net/gallery/showimage.php?i=1473&c=51

The attack states discard a Metal Energy CARD so does this mean that only Metal and Dark Metal can be discarded for this attack to work In a previous it seemed like anything that provides metal can be discarded heres a link for that also.

http://pokegym.net/forums/showthread.php?t=28068&highlight=delta+blast

The master Trainer states that the attack checks for the card to provide metal so does't that also mean multi (No other specials attached) and rainbow DRE Holon Poke can be discarded for the attack. It was ruled differently at our Gym and it may has cost my son a few games. All help is Appreciated. Holla

 

[PokePop]

Anything that provides Metal Energy counts as a Metal Energy card.
So you could discard a Rainbow, a Holon's Pokemon, a Scramble ( if you're behind in prizes), or even Basic Energy cards while Holon Research Tower is in play!

What your Gymleader may be getting confused about is rulings that require Basic Energy cards to be discarded.
If an attack says "discard a Basic {Fire} Energy card", then only a real Basic {Fire} Energy card will do. Rainbow won't. That's because "Basic" was specified. But in this case, "Basic" was not specified (not that there are any Basic Metal, anyway), and so any card that provides Metal can be discarded.

Hope that helps.