This is a beloved mechanic for good reason: it draws cards, incentivizes attacking, and adds a fun and simple mini-game to the larger game of Commander
These are alternate versions of existing cards, but as you can see, it wont keep them from dazzling anyone who finds one
Moreover, if one of the opponents Pokemon has damage, the Pierce the Pain move can deal 100 damage to it
Because of this cards potential, I think Venusaur deserves to be in third place
Madam Mim in particular can be trickier for new players, requiring the player to banish one of their own cards to bring out the shapeshifting witch - if you dont plan ahead, you might end up discarding one of the cards you needed
It was assisted by its relatively cheap casting cost for its stats, temporary hexproof, brilliant card draw, and dragon-powered spells like Silumgar's Scorn