Some players load their decks with as many efficient creatures as they can, sometimes taking advantage of creature type synergies
Basically any card that says when you perform your deck's dedicated action, draw a card is solid since it adds card advantage in addition to whatever you were doing
Once during your turn, when you play this Pokmon from your hand to evolve 1 of your Pokmon, you may put a Supporter card from your discard pile into your hand
The same can be said for decks that want permanents in play (Selfcraft Mechan, Embrace Oblivion, etc)
Call of Legends - Pokemon Card List and Prices
Once the deck can reliably trigger Coven and access new cards, it can showcase its greatest strength: getting large amounts of power and toughness into play