Plains

Baird, Steward of Argive

Vigilance
Creatures can't attack you or planeswalkers you control unless their controller pays {1} for each of those creatures.

Archon of Absolution

Flying
Protection from white (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything white.)
Creatures can't attack you or planeswalkers you control unless their controller pays {1} for each of those creatures.

Oath of Gideon

When Oath of Gideon enters, create two 1/1 white Kor Ally creature tokens.
Each planeswalker you control enters with an additional loyalty counter on it.

Archivist of Oghma

Flash
Whenever an opponent searches their library, you gain 1 life and draw a card.

Dawn Charm

Choose one —
• Prevent all combat damage that would be dealt this turn.
• Regenerate target creature.
• Counter target spell that targets you.

Strip Mine

{T}: Add {C}.
{T}, Sacrifice Strip Mine: Destroy target land.

Split Up

Choose one —
• Destroy all tapped creatures.
• Destroy all untapped creatures.

Lae'zel, Vlaakith's Champion

If you would put one or more counters on a creature or planeswalker you control or on yourself, put that many plus one of each of those kinds of counters on that permanent or player instead.
Choose a Background (You can have a Background as a second commander.)

Mangara, the Diplomat

Lifelink
Whenever an opponent attacks with creatures, if two or more of those creatures are attacking you and/or planeswalkers you control, draw a card.
Whenever an opponent casts their second spell each turn, draw a card.

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Duelist's Heritage

Whenever one or more creatures attack, you may have target attacking creature gain double strike until end of turn.

Extraplanar Lens

Imprint — When Extraplanar Lens enters, you may exile target land you control.
Whenever a land with the same name as the exiled card is tapped for mana, its controller adds one mana of any type that land produced.

Archaeomancer's Map

When Archaeomancer's Map enters, search your library for up to two basic Plains cards, reveal them, put them into your hand, then shuffle.
Whenever a land an opponent controls enters, if that player controls more lands than you, you may put a land card from your hand onto the battlefield.

The Chain Veil

At the beginning of your end step, if you didn't activate a loyalty ability of a planeswalker this turn, you lose 2 life.
{4}, {T}: For each planeswalker you control, you may activate one of its loyalty abilities once this turn as though none of its loyalty abilities have been activated this turn.

Tenuous Truce

Enchant opponent
At the beginning of enchanted opponent's end step, you and that player each draw a card.
When you attack enchanted opponent or a planeswalker they control or when they attack you or a planeswalker you control, sacrifice Tenuous Truce.

Teyo, Geometric Tactician

When Teyo, Geometric Tactician enters, create a 0/4 white Wall creature token with defender and flying.
+1: You and target opponent each draw a card.
−2: Choose left or right. Until your next turn, each player may attack only the nearest opponent in the last chosen direction and planeswalkers controlled by that opponent.

Paladin Class

(Gain the next level as a sorcery to add its ability.)
Spells your opponents cast during your turn cost {1} more to cast.
{2}{W}: Level 2
Creatures you control get +1/+1.
{4}{W}: Level 3
Whenever you attack, until end of turn, target attacking creature gets +1/+1 for each other attacking creature and gains double strike.

Gatewatch Beacon

Gatewatch Beacon enters with three loyalty counters on it.
{T}: Add {W}.
Whenever a planeswalker you control enters, if Gatewatch Beacon has loyalty counters on it, you may move a loyalty counter from Gatewatch Beacon onto that planeswalker.

Swords to Plowshares

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

Monk of the Open Hand

Flurry of Blows — Whenever you cast your second spell each turn, put a +1/+1 counter on Monk of the Open Hand.

Ascend from Avernus

Return all creature and planeswalker cards with mana value X or less from your graveyard to the battlefield. Exile Ascend from Avernus.

Tempt with Bunnies

Tempting Offer — Draw a card and create a 1/1 white Rabbit creature token. Then each opponent may draw a card and create a 1/1 white Rabbit creature token. For each opponent who does, you draw a card and you create a 1/1 white Rabbit creature token.

Deification

As Deification enters, choose a planeswalker type.
Planeswalkers you control of the chosen type have hexproof.
As long as you control a creature, if damage dealt to a planeswalker you control of the chosen type would result in all loyalty counters on it being removed, instead all but one of those counters are removed.

Pearl Medallion

White spells you cast cost {1} less to cast.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Trouble in Pairs

If an opponent would begin an extra turn, that player skips that turn instead.
Whenever an opponent attacks you with two or more creatures, draws their second card each turn, or casts their second spell each turn, you draw a card.

Throne of Eldraine

As Throne of Eldraine enters, choose a color.
{T}: Add four mana of the chosen color. Spend this mana only to cast monocolored spells of that color.
{3}, {T}: Draw two cards. Spend only mana of the chosen color to activate this ability.

Get Lost

Destroy target creature, enchantment, or planeswalker. Its controller creates two Map tokens. (They're artifacts with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Builder's Talent

(Gain the next level as a sorcery to add its ability.)
When Builder's Talent enters, create a 0/4 white Wall creature token with defender.
{W}: Level 2
Whenever one or more noncreature, nonland permanents you control enter, put a +1/+1 counter on target creature you control.
{4}{W}: Level 3
When this Class becomes level 3, return target noncreature, nonland permanent card from your graveyard to the battlefield.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Onakke Oathkeeper

Creatures can't attack planeswalkers you control unless their controller pays {1} for each creature they control that's attacking a planeswalker you control.
{4}{W}{W}, Exile Onakke Oathkeeper from your graveyard: Return target planeswalker card from your graveyard to the battlefield.

Elspeth's Talent

Enchant planeswalker
Enchanted planeswalker has "[+1]: Create three 1/1 white Soldier creature tokens."
Whenever you activate a loyalty ability of enchanted planeswalker, creatures you control get +2/+2 and gain vigilance until end of turn.

Elspeth Conquers Death

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Exile target permanent an opponent controls with mana value 3 or greater.
II — Noncreature spells your opponents cast cost {2} more to cast until your next turn.
III — Return target creature or planeswalker card from your graveyard to the battlefield. Put a +1/+1 counter or a loyalty counter on it.

Grand Master of Flowers

As long as Grand Master of Flowers has seven or more loyalty counters on him, he's a 7/7 Dragon God creature with flying and indestructible.
+1: Target creature without first strike, double strike, or vigilance can't attack or block until your next turn.
+1: Search your library and/or graveyard for a card named Monk of the Open Hand, reveal it, and put it into your hand. If you search your library this way, shuffle.

Semester's End

Exile any number of target creatures and/or planeswalkers you control. At the beginning of the next end step, return each of them to the battlefield under its owner's control. Each of them enters with an additional +1/+1 counter on it if it's a creature and an additional loyalty counter on it if it's a planeswalker.

Fateful Absence

Destroy target creature or planeswalker. Its controller investigates. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Wrath of God

Destroy all creatures. They can't be regenerated.

Terrain Generator

{T}: Add {C}.
{2}, {T}: You may put a basic land card from your hand onto the battlefield tapped.

Grateful Apparition

Flying
Whenever Grateful Apparition deals combat damage to a player or planeswalker, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)