Since their adoption of
Wrenn and Six, Temur
Delver variants have become dominant in Legacy. In Magic Online league play over recent weeks, Temur Delver has maintained a 56.5% win rate and earned over three times as many 5-0 finishes as the next deck. Most importantly, it has a favorable matchup against each of the other ten most-played decks.
While a strong card in general,
Wrenn and Six is especially powerful in Legacy because of its interaction with
Wasteland and the historic prevalence of metagame-defining 1-toughness creatures like
Mother of Runes;
Thalia, Guardian of Thraben; and
Young Pyromancer. Prior to the addition of Wrenn and Six to Temur Delver decks, the Legacy metagame was generally looking healthy. In order to weaken Temur Delver decks and bring the metagame into a better balance again, Wrenn and Six is banned in Legacy.