Whitemane Lion

Flash
When Whitemane Lion enters, return a creature you control to its owner's hand.

Reverent Hoplite

When Reverent Hoplite enters, create a number of 1/1 white Human Soldier creature tokens equal to your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)

Leonin Skyhunter

Veteran Armorsmith

Other Soldier creatures you control get +0/+1.

Magnifying Glass

{T}: Add {C}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Conclave Equenaut

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying

Seal of Cleansing

Sacrifice Seal of Cleansing: Destroy target artifact or enchantment.

Fanatical Devotion

Sacrifice a creature: Regenerate target creature.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Citizen's Arrest

When Citizen's Arrest enters, exile target creature or planeswalker an opponent controls until Citizen's Arrest leaves the battlefield.

Loxodon Restorer

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
When Loxodon Restorer enters, you gain 4 life.

Daybreak Chimera

This spell costs {X} less to cast, where X is your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)
Flying

Knight of Old Benalia

Suspend 5—{W} (Rather than cast this card from your hand, you may pay {W} and exile it with five time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)
When Knight of Old Benalia enters, other creatures you control get +1/+1 until end of turn.

Answered Prayers

Whenever a creature you control enters, you gain 1 life. If Answered Prayers isn't a creature, it becomes a 3/3 Angel creature with flying in addition to its other types until end of turn.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Marble Diamond

Marble Diamond enters tapped.
{T}: Add {W}.

Gossamer Chains

Return Gossamer Chains to its owner's hand: Prevent all combat damage that would be dealt by target unblocked creature this turn.

Arcane Signet

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

Spirited Companion

When Spirited Companion enters, draw a card.

Minimus Containment

Enchant nonland permanent
Enchanted permanent is a Treasure artifact with "{T}, Sacrifice this artifact: Add one mana of any color," and it loses all other abilities. (If it was a creature, it's no longer a creature.)

Soul Warden

Whenever another creature enters, you gain 1 life.

Oblivion Ring

When Oblivion Ring enters, exile another target nonland permanent.
When Oblivion Ring leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Nahiri's Binding

Enchant creature or planeswalker
Enchanted permanent can't attack or block, and its activated abilities can't be activated.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Ajani's Sunstriker

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Isolation Zone

When Isolation Zone enters, exile target creature or enchantment an opponent controls until Isolation Zone leaves the battlefield. (That permanent returns under its owner's control.)

Healer's Hawk

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Ampryn Tactician

When Ampryn Tactician enters, creatures you control get +1/+1 until end of turn.

Priest of Ancient Lore

When Priest of Ancient Lore enters, you gain 1 life and draw a card.

Basri's Acolyte

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When Basri's Acolyte enters, put a +1/+1 counter on each of up to two other target creatures you control.

Cathar Commando

Flash (You may cast this spell any time you could cast an instant.)
{1}, Sacrifice this creature: Destroy target artifact or enchantment.

Basilica Shepherd

Flying
When Basilica Shepherd enters, create two 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block." (Players dealt combat damage by them also get a poison counter.)

Thraben Inspector

When Thraben Inspector enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Inspiring Overseer

Flying
When this creature enters, you gain 1 life and draw a card.

Reprobation

Enchant creature
Enchanted creature loses all abilities and is a Coward creature with base power and toughness 0/1. (It keeps all supertypes but loses all other types and creature types.)