Vanguard Fireteam

Begin the game with Vanguard Fireteam in play.
As long as Vanguard Fireteam is in play, you may
only have up to three Guardian creatures on the
battlefield and can play Legendary Dungeons.
When Vanguard Fireteam is removed from play,
you get an emblem named Vanguard Raid
Fireteam with "You may only have up to six
Guardian creatures on the battlefield and can
play Legendary Dungeons and Raids."