IIRC in Yugioh there is only a certain number of Blue-Eyes (from the show?), so you could put a rule on the card 'there may only be X Blue-Eyes on the battlefield at any time', Star Wars CCG used to have permanents that you could have 2 or 3 copies of in play, in addition to stuff you could only have 1 of, the concept would work fine here too, only this could care about both players' boards
Pull rates for VS Pokmon cards are relatively low, as holo rares were much harder to obtain compared to modern sets
Everyone has rulings against them so if that happens then try not to get too eaten up about it, move on and concentrate on winning the rest of the games in front of you
Spending mana is the foundation of Magic: The Gathering
A five drop in Modern needs to be way stronger
Choose either a Pokmon Tool card or Stadium card in play (yours or your opponent's) and put it in the Lost Zone