Phyrexian Unlife (Step-and-Compleat Foil) (SLD-1213) - Secret Lair Drop (Borderless) Foil

You don't lose the game for having 0 or less life.
As long as you have 0 or less life, all damage is dealt to you as though its source had infect. (Damage is dealt to you in the form of poison counters.)