Relentless Gravelord

As an additional cost to cast this spell, sacrifice three permanents.
Vanishing 2, Annihilator 5
If there are 8 or more creature cards in all graveyards, Relentless Gravelord gains haste.
Dredge 4 (If you would draw a card, instead you may put exactly four cards from the top of your library into your graveyard. If you do, return this card from your graveyard to your hand.)