Horizon Canopy

{T}, Pay 1 life: Add {G} or {W}.
{1}, {T}, Sacrifice Horizon Canopy: Draw a card.

Castle Ardenvale

Castle Ardenvale enters tapped unless you control a Plains.
{T}: Add {W}.
{2}{W}{W}, {T}: Create a 1/1 white Human creature token.

Snow-Covered Plains

Daxos, Blessed by the Sun

Daxos's toughness is equal to your devotion to white. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)
Whenever another creature you control enters or dies, you gain 1 life.

Martyr of Sands

{1}, Reveal X white cards from your hand, Sacrifice Martyr of Sands: You gain three times X life.

Soul Warden

Whenever another creature enters, you gain 1 life.

Honor of the Pure

Heliod, Sun-Crowned

Indestructible
As long as your devotion to white is less than five, Heliod isn't a creature.
Whenever you gain life, put a +1/+1 counter on target creature or enchantment you control.
{1}{W}: Another target creature gains lifelink until end of turn.

Flagstones of Trokair

{T}: Add {W}.
When Flagstones of Trokair is put into a graveyard from the battlefield, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Serra Ascendant

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
As long as you have 30 or more life, Serra Ascendant gets +5/+5 and has flying.

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Auriok Champion

Protection from black and from red
Whenever another creature enters, you may gain 1 life.

Proclamation of Rebirth

Return up to three target creature cards with mana value 1 or less from your graveyard to the battlefield.
Forecast — {5}{W}, Reveal Proclamation of Rebirth from your hand: Return target creature card with mana value 1 or less from your graveyard to the battlefield. (Activate only during your upkeep and only once each turn.)

Ranger-Captain of Eos

When Ranger-Captain of Eos enters, you may search your library for a creature card with mana value 1 or less, reveal it, put it into your hand, then shuffle.
Sacrifice Ranger-Captain of Eos: Your opponents can't cast noncreature spells this turn.

Walking Ballista

Walking Ballista enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

Ajani's Pridemate

Whenever you gain life, put a +1/+1 counter on Ajani's Pridemate.

Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.