Phyrexian Unlife

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.)

Snow-Covered Swamp

Plains

Dire Tactics

Exile target creature. If you don't control a Human, you lose life equal to that creature's toughness.

Wall of Blood

Defender (This creature can't attack.)
Pay 1 life: Wall of Blood gets +1/+1 until end of turn.

Idyllic Tutor

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Soul Conduit

{6}, {T}: Two target players exchange life totals.

Solemnity

Players can't get counters.
Counters can't be put on artifacts, creatures, enchantments, or lands.