Plains

Concerted Effort

At the beginning of each upkeep, creatures you control gain flying until end of turn if a creature you control has flying. The same is true for fear, first strike, double strike, landwalk, protection, trample, and vigilance.

Order of the Stars

Defender (This creature can't attack.)
As Order of the Stars enters, choose a color.
Order of the Stars has protection from the chosen color.

Arcane Encyclopedia

Painter's Servant

As Painter's Servant enters, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.

Devout Lightcaster

Protection from black
When Devout Lightcaster enters, exile target black permanent.

Haazda Marshal

Whenever Haazda Marshal and at least two other creatures attack, create a 1/1 white Soldier creature token with lifelink.

History of Benalia

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Create a 2/2 white Knight creature token with vigilance.
III — Knights you control get +2/+1 until end of turn.

Auriok Champion

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

Mirran Crusader

Double strike, protection from black and from green

Crystal Ball

{1}, {T}: Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Segovian Angel

Thraben Doomsayer

{T}: Create a 1/1 white Human creature token.
Fateful hour — As long as you have 5 or less life, other creatures you control get +2/+2.

Windborn Muse

Flying
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Memorial to Glory

Memorial to Glory enters tapped.
{T}: Add {W}.
{3}{W}, {T}, Sacrifice Memorial to Glory: Create two 1/1 white Soldier creature tokens.