The Dark Soul

There can only be one Dark Soul in the game.
You cant lose the game. At your endstep all your opponents mill three cards and sacrifice a
creature.
From the Dark came beings who claimed souls near
the First Flame; 4 of these became the Lords who
claimed the mightiest and most brilliant of souls.
While the other three "Lords" found larger souls,
there was a fourth, a lowly and forgotten being known
as the Furtive Pygmy. His soul was the Dark Soul.