Obscure dawn

{t}: put a +1/+1 counter in a black creature until it blocks another creature.
{b}{b}, sacrifice a creature with a mana value less than 3: an opponent discards as much cards as the mana value of the sacrified creature.
{4}{b}, sacrifice obscure dawn: exile all cementeries on the board, every player returns one card from the exile to his hand. One black creature you control gains lifelink and indestructible.