Because of Transform, this has a fair number of targets against black, red, and green decks, but Id be reticent to run more than one at the beginning of the format
When you play this Pokmon from your hand onto your Bench, you may put 2 Basic Pokmon (except for Dragonite-EX) from your discard pile into your hand
If one player has fewer cards than required, that player loses
Note that's not planeswalkers so you cannot target them for loyalty counter doubling since it says each kind of counter, not just +1/+1, like Shield or energy counters on artifacts (or...say....fellowship counters...) She's great fun for the masses leading a Commander deck
Though Leos got 3,200 ATK, there are too many ways to get rid of this card for it to be very practicalparticularly since the player can have NO spells or traps in the spell/trap card zone to use the effect
You have to balance all of these effects