It helps fix the discrepancy between tokens and +1/+1 counters by only making a single token, although that token is usually bigger (you get N +1/+1 counters or an N/N white Spirit creature token)
Here's the build you should aim for: Mewtwo ex x2 Drowzee x2 Hypno x2 Potion x2 X Speed x2 Poke Ball x2 Red Card x2 Professor's Research x2 Sabrina x2 Giovanni x2 Drowzee and Hypno can also hold up as decent fighters while you wait to draw Mewtwo ex, but honestly the key here, as with the other two decks, is delaying tactics to set up the Psydrive attack
Goldeen is a water-type Pokmon and its sole, terrible attack, requires a single water energy card
Even if you had to use Summoner's Pact or Pact of Negation in the process, you can use Consign to Memory to counter their "lose the game" triggers in your next upkeep
As it provides additional damage and long-distance sniping, it further increases stability
Stamp Collectors, Rejoice