Phyrexian Unlife | Magic: The Gathering
Formats Phyrexian Unlife is Legal in
Official Oracle Text for Phyrexian Unlife
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.)
Official Rulings for Phyrexian Unlife
6/1/2011 : If you're at 0 or less life and Phyrexian Unlife leaves the battlefield, you'll lose the game (unless some other effect is keeping you from losing).
6/1/2011 : If you're at 0 or less life, you can't pay any amount of life except 0.
6/1/2011 : You can still lose the game for other reasons, including having ten or more poison counters or drawing a card from a library with no cards in it.