Triskaidekaphobia

At the beginning of your upkeep, choose one —
• Each player with exactly 13 life loses the game, then each player gains 1 life.
• Each player with exactly 13 life loses the game, then each player loses 1 life.

Lich's Tomb

You don't lose the game for having 0 or less life.
Whenever you lose life, sacrifice a permanent for each 1 life you lost. (Damage causes loss of life.)

Lich's Mastery

Hexproof
You can't lose the game.
Whenever you gain life, draw that many cards.
Whenever you lose life, for each 1 life you lost, exile a permanent you control or a card from your hand or graveyard.
When Lich's Mastery leaves the battlefield, you lose the game.

Gideon of the Trials

+1: Until your next turn, prevent all damage target permanent would deal.
0: Until end of turn, Gideon of the Trials becomes a 4/4 Human Soldier creature with indestructible that's still a planeswalker. Prevent all damage that would be dealt to him this turn.
0: You get an emblem with "As long as you control a Gideon planeswalker, you can't lose the game and your opponents can't win the game."

Repay in Kind

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

Profane Transfusion

Two target players exchange life totals. You create an X/X colorless Horror artifact creature token, where X is the difference between those players' life totals.

Reverse the Sands

Redistribute any number of players' life totals. (Each of those players gets one life total back.)

Magus of the Mirror

{T}, Sacrifice Magus of the Mirror: Exchange life totals with target opponent. Activate only during your upkeep.

Soul Conduit

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

Axis of Mortality

At the beginning of your upkeep, you may have two target players exchange life totals.

Cloudsteel Kirin

Flying
Equipped creature has flying and "You can't lose the game and your opponents can't win the game."
Reconfigure {5} ({5}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)