This is a list I made for a Cobalion-Klinklang deck. Below the list are a few long paragraphs of explanations and notes.
3-0-4 Klink BW and Klinklang 3 PS 1 BW
2 Cobalion EX PS
2 Cobalion NV
4 N DE
4 Juniper DE
3 Cheren DE
2 Skyla BC
4 Pokemon Catcher EP
4 Switch BC
4 Rare Candy DE
3 Ether PS
3 Ultra Ball DE
2 Pokedex BW
2 Eviolite NV
2 Max Potion EP
1 Super Rod DV
1 Computer Search BC
1 Tool Scrapper DR
9 metal energies
Cobalion EX Metal HP 180 Basic
(M) Holy Edge 30
Discard a Special Energy attached to the defending Pokemon.
(M)(M)© Steel Bullet 100
This attack's damage isn't affected by Weakness, Resistance, or any other effects on the Defending Pokemon.
Weakness: Fire x2/Resistance:Psychic -20/Retreat cost: 2
Klinklang Metal HP 140 Stage 2 (Team Plasma)
Ability: Plasma Steel: Prevent all effects from attacks, including damage, done to your Metal Pokemon from your opponent's Pokemon EX.
(M)(M)© Heavy Bullet 70
Flip a coin. If heads, this attack does 20 damage to 1 of your opponent's Benched Pokemon (Don't apply Weakness or Resistance for Benched Pokemon).
Weakness: Fire x2/Resistence: Psychic -20/ Retreat cost: 2
Lots of stuff: The aim of this deck is to use Klinklang's Plasma Steel ability to grant protection to all your metal types, and then sweep from there. Works great since a large portion of the metagame's decks rely on EXs. Cobalion EX , the main attacker, two-shots all EXs (excluding colorless EX + Big Cape + Aspertia lol) and also destroys two cards which would otherwise give this deck a hard time: Bouffalant DR and Sigilyph DR.
Now to the vast multitude of problems of this deck. I'm not too trustworthy of Ether, so if it doesn't work then there isn't any energy acceleration. Thus it can lose to Hammers.This deck also has a hard time retreating (no pun intended). Also, since the most you are aiming to hit is 100, this deck gets annoyed by decks that can heal, e.g Darkrai/Hydreigon and Keldeo/Blastoise (what irony, the two other stage two decks!). In fact, those two decks can run pokemon which give this deck a hard time, such as Giratina EX and Keldeo BC47. Finally, Garbodor also takes away the immunity, but Cobalion EX still has a chance, providing it gets set up.
A few (/another paragraph of) notes: You can give this deck a more defensive stance by adding in Registeel EX and other stuff, but I prefer a more offensive edge to this deck, thus only Cobalions. If Garbodor is a problem, switching the number of Eviolites and Tool Scrappers is an option. Eviolite is mainly around for the early game when PS Klinklang isn't around. I put in one BW Klinklang because you can move around energies + Max Potion, but Max Potion works on its own, plus getting PS Klinklang out has a higher priority.
Advice is deeply appreciated, especially on beating the problems. Any ways on adding more energies? Any problems to this deck I haven't mentioned or realised? Here's one: Victini NV15