Cursed Graveyard

At the beginning of each player's upkeep, that
player sacrifices a creature.
If they can't, they lose 3 life.
Whenever a creature card is put into a graveyard
from the battlefield, you may pay {1}{b}. If you do,
create a black 1/1 Shade creature token with flying.
"The land itself rejects the presence of the living, condemning them to an unending cycle of death and
decay."