Horn of Valere

You may only have one Horn of Valere in your deck
If Horn of Valere is drawn during a draw phase, reveal and shuffle back into library.
{6},Tap Legendary Creature, Exile Horn of Valere: Return all Legendary Creatures from all graveyards and exile area to the battlefield under your control. They gain haste. Return cards to where they came from at end of turn.
The grave is no barrier to my call.