Veyka, The Dread Scaled

Deathtouch, flying, Ward- pay 7 life
As long as there are at least seven creature cards
in your graveyard, Veyka has indestructible.
Whenever a dragon you control attacks, choose
one that hasn't been chosen yet this turn —
• Each other creature gets -7/-7 until end of turn.
• Each opponent loses 7 life and you gain 7 life.
• Mill seven cards.