Bringer of the Blue Dawn

Commander is where Bringer of the Blue Dawn sees virtually all of its play — four opponents means drawing an extra three cards per round on top of your normal draw, which is a legitimate card advantage engine stapled to a threat. In Legacy and Vintage it's a nine-mana do-nothing-until-your-next-turn creature in formats that win on turns one through three, so it never sees a table there despite being legal. Modern is similarly inhospitable; the curve stops well before nine, and the five-color pip requirement is a non-starter in a format without reliable five-color fixing. Oathbreaker is the only other realistic home, and even there it competes for late-game slots against cheaper threats.