Only cards from Diamond and Pearl, Mysterious Treasures, Secret Wonders, and Great Encounters are allowed. However, Energy cards from previous sets are also allowed.
x3 Magnemite (D&P)-Resonance is a decent two for 20 that is a two for 40 if the opponent is confused. Also has resistance to Psychic. Needed for evolution.
x2 Magneton (D&P)-Tri Attack can do 60 damage for two energy and Magnetic Ray is a three for 40 that acts as a mini Gust of Wind. Also has resistance to Psychic. Needed for evolution.
x1 Magenzone (D&P)-120 HP and resistance to Psychic. Magnezone is kind of needed for this deck because of Magnetize, which gives my Steel types with energy on them a retreat cost of zero. Needed considering they mostly have a retreat cost of three or four. Metal Burst is also a solid attack, a three for 50 that does 10 more damage for each energy on Magnezone.
x2 Shieldon (MT)-Hard Face is a solid two for 20 attack that reduces damage I take by 20 during my opponent's next turn. Shield Attack can do 60 damage for three energy. Also has resistance to Psychic. Needed for evolution.
x1 Bastiodon (MT)-130 HP and resistance to Psychic. Protective Wall is nice as it prevents bench damage to me. Anger Revenge is a good attack. It is a three for 60 that does 40 damage to a benched Pokemon if Bastiodon was damaged by an attack my opponent's last turn. This can deter my opponent from atttacking sometimes.
x3 Onix (D&P)-A 90 HP basic. Needed for evolution.
x3 Steelix (D&P)-110 HP and resistance to Psychic. Slam is a good attack, it can do 60 damage for one energy. Metal Slash is a good attack to use if Steelix is about to be KOd, it is a four for 100.
x3 Skarmory (GE)-A 70 HP basic with resistance to Psychic. Air Crash is a great one for 20 attack with a chance for energy removal. And Steel Wing is a solid three for 40 that keeps Skarmory alive (especially with Special Metal Energy) by reducing damage it takes my opponent's next turn by 20.
x4 Warp Point (D&P)-A Switch and a Gust of Wind in one card.
x4 Roseanne's Research (SW)-Gets me Pokemon and Energy.
x4 Team Galactic's Mars (SW)-Drawing and puts a card in my opponent's hand to the bottom of their deck.
x4 Leftovers (GE)-Healing.
x3 Rival (D&P)-Gets me cards.
x3 Armor Fossil (MT)-Needed for evolution.
x16 Steel Energy-Needed.
x4 Metal Energy (Mysterious Treasures)-Provides steel energy while also reducing damage my Steel types take by 10.