Soul Warden

Whenever another creature enters, you gain 1 life.

Disenchant

Plains

Celestial Unicorn

Whenever you gain life, put a +1/+1 counter on Celestial Unicorn.

Pacifism

Enchant creature
Enchanted creature can't attack or block.

Angelic Edict

Soulmender

Pride Guardian

Defender
Whenever Pride Guardian blocks, you gain 3 life.

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.)

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.