Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Children of Korlis

Sacrifice Children of Korlis: You gain life equal to the life you've lost this turn. (Damage causes loss of life.)

Delaying Shield

If damage would be dealt to you, put that many delay counters on Delaying Shield instead.
At the beginning of your upkeep, remove all delay counters from Delaying Shield. For each delay counter removed this way, you lose 1 life unless you pay {1}{W}.

Words of Worship

{1}: The next time you would draw a card this turn, you gain 5 life instead.

Sol Ring

Queza, Augur of Agonies

Whenever you draw a card, target opponent loses 1 life and you gain 1 life.

Command Tower

Beseech the Mirror

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
Search your library for a card, exile it face down, then shuffle. If this spell was bargained, you may cast the exiled card without paying its mana cost if that spell's mana value is 4 or less. Put the exiled card into your hand if it wasn't cast this way.

Trouble in Pairs

If an opponent would begin an extra turn, that player skips that turn instead.
Whenever an opponent attacks you with two or more creatures, draws their second card each turn, or casts their second spell each turn, you draw a card.

Enlightened Tutor

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Lich

As Lich enters, you lose life equal to your life total.
You don't lose the game for having 0 or less life.
If you would gain life, draw that many cards instead.
Whenever you're dealt damage, sacrifice that many nontoken permanents. If you can't, you lose the game.
When Lich is put into a graveyard from the battlefield, you lose the game.

Tainted Sigil

{T}, Sacrifice Tainted Sigil: You gain life equal to the total life lost by all players this turn. (Damage causes loss of life.)

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Sheoldred, the Apocalypse

Deathtouch
Whenever you draw a card, you gain 2 life.
Whenever an opponent draws a card, they lose 2 life.

Pact Weapon

As long as Pact Weapon is attached to a creature, you don't lose the game for having 0 or less life.
Whenever equipped creature attacks, draw a card and reveal it. The creature gets +X/+X until end of turn and you lose X life, where X is that card's mana value.
Equip—Discard a card.

Morphic Pool

Morphic Pool enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

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.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.