The Test of Humanity

Enchant player
At the beginning of enchanted player's upkeep,
put a pain counter on The Test of Humanity.
At the end of enchanted player's upkeep, that player
loses life equal to the number of pain counters on
The Test of Humanity.
When there are six or more pain counters
on The Test of Humanity, exile it. When you do,
the enchanted player gains life equal to
the life lost from The Test of Humanity.
The enchanted player may exile this card at any time. If they do, they lose the game.