Melmetal Regeneration

This deck relies heavily on getting Meltan on the field turn 1 and getting the Caterpie line on your bench quickly, but if done properly it can easily result in a Melmetal that regenerates 40 HP every turn, effectively negating 60 damage and allowing it to rampage. This can potentially rise to 80 with a Potion use, allowing it to wall out Pikachu EX and Starmie EX. Odds are against this deck, but when the stars align, it can outright crush some strong meta decks, and it's probably going to take something capable of dealing 150 or more damage in a single move to put down effectively.