The Avenging Valkyrie

Flying, Vigilance, Battlecry, Flash
When The Avenging Valkyrie enters the
battlefield return up to 3 creatures cards from
your graveyard each with a converted mana cost
of 3 or less to the battlefield with an einherjar
counter and a haste counter.
When Avenging Valkyrie leaves the battlefield sacrifice all creatures with an einherjar
counter.