This effect doesnt come much cheaper, so these show up in aristocrat decks across formats
As you might already know, when youre playing in a sanctioned (read: official) tournament, each player has the opportunity to mulligan their opening hand at the beginning of the game: if they dont like what they draw, they can shuffle their hand back into their deck and draw a new hand with one fewer card
4 Emerald/Ruby Ruby has another interesting pairing for aggro decks with the Emerald/Ruby strategy, constituting the biggest exception to Amber's dominance in aggressive play
It cares about the gap between your creatures power and toughness rather than just their toughness, so youre incentivized to go for a form of efficiency
Richard: That seems right
However, these are not considered part of a standard deck.