Plains

Squadron Hawk

Flying
When Squadron Hawk enters, you may search your library for up to three cards named Squadron Hawk, reveal them, put them into your hand, then shuffle.

Authority of the Consuls

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

Soul Warden

Whenever another creature enters, you gain 1 life.

Spirited Companion

When Spirited Companion enters, draw a card.

Martyr of Sands

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

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

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.

Imperial Recovery Unit

Whenever Imperial Recovery Unit attacks, return target creature or Vehicle card with mana value 2 or less from your graveyard to your hand.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

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.

Ranger of Eos

When Ranger of Eos enters, you may search your library for up to two creature cards with mana value 1 or less, reveal them, put them into your hand, then shuffle.

Vesperlark

Flying
When Vesperlark leaves the battlefield, return target creature card with power 1 or less from your graveyard to the battlefield.
Evoke {1}{W} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

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.