No one wants to be duped into paying hundreds for counterfeit cards, and Creatures Inc
Heck, Widow's Walk ability is so situational, that it might not even align well with typical Limited strategies, where attacking with multiple creatures is often preferred
They read, Whenever Zur the Enchanter attacks, you may search your library for an enchantment card with mana value 3 or less, put it onto the battlefield, then shuffle. That means you can find whatever answer you need whenever they attack
Pre-release and Draft Events Pre-release and draft events are excellent opportunities to build your collection and trade cards
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
