Repay in Kind

Each player's life total becomes the lowest life total among all players.

Pulse of the Fields

You gain 4 life. Then if an opponent has more life than you, return Pulse of the Fields to its owner's hand.

Wall of Blood

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

Angelic Enforcer

Flying
You have hexproof.
Angelic Enforcer's power and toughness are each equal to your life total.
Whenever Angelic Enforcer attacks, double your life total.

Enduring Angel

Flying, double strike
You have hexproof.
If your life total would be reduced to 0 or less, instead transform Enduring Angel and your life total becomes 3. Then if Enduring Angel didn't transform this way, you lose the game.

Enduring Angel // Angelic Enforcer

Worship

If you control a creature, damage that would reduce your life total to less than 1 reduces it to 1 instead.

Angel's Grace

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
You can't lose the game this turn and your opponents can't win the game this turn. Until end of turn, damage that would reduce your life total to less than 1 reduces it to 1 instead.