Of course, this would simply lead to some players being able to play with basically eight copies of a card in Legacy unless they banned the original duals at the same time, which opens up an entirely different can of worms
Since Simic (green/blue) colors have plenty of ways to pump the stats of your creatures, this makes reaching ten damage in just one turn trivial, thanks to all the auras and instants it has
Best Buy will do the same, but with a Bulbasaur promo card
Fusion Summon 1 "Vehicroid" Fusion Monster from your Extra Deck, using monsters from your hand or field as Fusion Materials, and if you do, it cannot be destroyed by card effects, and its effects cannot be negated
Three goblins, one Inspector or Epicure, plus a turn two land provide enough mana to convoke a chunky Knight-Errant of Eos into play
Each copy targets a different one of them