Case of the Uneaten Feast

Whenever a creature you control enters, you gain 1 life.
To solve — You've gained 5 or more life this turn. (If unsolved, solve at the beginning of your end step.)
Solved — Sacrifice this Case: Creature cards in your graveyard gain "You may cast this card from your graveyard" until end of turn.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Soul Warden

Whenever another creature enters, you gain 1 life.

Curse of Silence

Enchant player
As this Aura enters, choose a card name.
Spells with the chosen name enchanted player casts cost {2} more to cast.
Whenever enchanted player casts a spell with the chosen name, you may sacrifice this Aura. If you do, draw a card.

Aminatou, the Fateshifter

+1: Draw a card, then put a card from your hand on top of your library.
−1: Exile another target permanent you own, then return it to the battlefield under your control.
−6: Choose left or right. Each player gains control of all nonland permanents other than Aminatou controlled by the next player in the chosen direction.
Aminatou, the Fateshifter can be your commander.

Luminous Phantom

Flying
Whenever another creature you control leaves the battlefield, you gain 1 life.
If Luminous Phantom would be put into a graveyard from anywhere, exile it instead.

Lunarch Veteran

Whenever another creature you control enters, you gain 1 life.
Disturb {1}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Lunarch Veteran // Luminous Phantom

Ajani's Welcome

Whenever a creature you control enters, you gain 1 life.

Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.