Voice of the Blessed

Whenever you gain life, put a +1/+1 counter on Voice of the Blessed.
As long as Voice of the Blessed has four or more +1/+1 counters on it, it has flying and vigilance.
As long as Voice of the Blessed has ten or more +1/+1 counters on it, it has indestructible.

Soul Warden

Whenever another creature enters, you gain 1 life.

Horn of Gondor

When Horn of Gondor enters, create a 1/1 white Human Soldier creature token.
{3}, {T}: Create X 1/1 white Human Soldier creature tokens, where X is the number of Humans you control.

Seasoned Cathar

Ambitious Farmhand

When Ambitious Farmhand enters, you may search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
Coven — {1}{W}{W}: Transform Ambitious Farmhand. Activate only if you control three or more creatures with different powers.

Ambitious Farmhand // Seasoned Cathar

Gathering Throng

When Gathering Throng enters, you may search your library for any number of cards named Gathering Throng, reveal them, put them into your hand, then shuffle.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Lay Down Arms

Exile target creature with mana value less than or equal to the number of Plains you control. Its controller gains 3 life.

Swords to Plowshares

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

Plains

Banishing Slash

Destroy up to one target artifact, enchantment, or tapped creature. Then if you control an artifact and an enchantment, create a 2/2 white Samurai creature token with vigilance.

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.