The deck's engine starts with Genesect ex. Its Metallic Signal Ability lets you search your deck for up to two Evolution Metal Pokémon and put them into your hand once per turn. In practice that means pulling Metang and Metagross copies early, or fetching the Mega Excadrill ex you need to attack. Getting Genesect ex active on your first or second turn sets up everything that follows.

Metang is the energy accelerator the whole plan depends on. Its Metal Maker Ability lets you look at the top four cards of your deck and attach any number of Basic Metal Energy cards you find there to your Pokémon in any way you like, shuffling the rest to the bottom. With four copies of Metang available, you can trigger Metal Maker once per Metang per turn - spreading Metal Energy across your Bench and loading Mega Excadrill ex far faster than a single manual attachment would allow. Fifteen Basic Metal Energy in the deck means Metal Maker reliably finds something to attach.

Once Mega Excadrill ex is ready, the attacks are straightforward but punishing. Undermine costs two Metal Energy, does 90 damage, and discards the top two cards of your opponent's deck - useful early when you want to attack without committing five Energy. Maximum Drilling costs three Metal Energy and does 200 damage base; if this Pokémon has at least two extra Energy attached beyond that three-Energy cost, the attack does 130 more damage for a total of 330. That threshold is reachable with the Metal Maker engine running across multiple Metang.

Metagross provides a secondary attacking route and disruption. Bounce Back for one Metal Energy does 60 damage and switches out your opponent's Active Pokémon, with your opponent choosing the replacement. Metallic Hammer costs four Energy and does 150 damage base, or 300 if you discard three Metal Energy from Metagross. Energy Recycler is in the list specifically to shuffle up to five Basic Energy from your discard pile back into your deck, keeping the supply available for Metal Maker to find again. Shaymin's Flower Curtain Ability prevents all damage done to your Benched Pokémon that don't have a Rule Box by your opponent's attacks, protecting the Metang and Beldum sitting on your Bench while they wait to use Metal Maker or evolve.