Pokémon
Mew ex x2
Dialga ex x2
Arceus ex x2
Trainers
Potion x1
X Speed x2
Poké Ball x2
Professor's Research x2
Giant Cape x1
Rocky Helmet x1
Giovanni x1
Sabrina x1
Leaf x1
Cyrus x1
Adaman x1
Strategy
Steel energy only!
Saw this deck concept, tried it and it worked, so I thought I might post it here...
The idea is to get Dialga in the Active spot as soon as possible and start giving away energy to Arceus and Mew on the bench. Mew is there to try to deal with opposing Charizard and other heavy hitters.
We have only 6 basic pokémon cards here with ways to get the bench full for Arceus.
You can really put any trainer cards there. I chose Giovanni to deal a bit more damage to OHKO opposing Arceus. I also chose to prioritize switching cards so switching wouldn't cost me that much energy. I can imagine putting more Sabrina cards there or Cyrus or Pokédex Communications, whichever you feel comfortable. You may also think about Shaymin A2a as his ability helps with switching.