Silencer's Sigil

When Silencer's Sigil enters the battlefield,
choose a card name. Cards with the chosen
name can't be cast.
At the beginning of each player's upkeep,
that player may choose another card name.
If they do, they lose 2 life. Then if seven or
more card names have been chosen, exile
all cards named Silencer's Sigil and each
player's life total becomes 1.