Tevesh Szat, Doom of Fools

+2: Create two 0/1 black Thrull creature tokens.
+1: You may sacrifice another creature or planeswalker. If you do, draw two cards, then draw another card if the sacrificed permanent was a commander.
−10: Gain control of all commanders. Put all commanders from the command zone onto the battlefield under your control.
Tevesh Szat, Doom of Fools can be your commander.
Partner

Secure the Wastes

Create X 1/1 white Warrior creature tokens.

Ancient Tomb

{T}: Add {C}{C}. This land deals 2 damage to you.

Oketra's Monument

White creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Shorikai, Genesis Engine

{1}, {T}: Draw two cards, then discard a card. Create a 1/1 colorless Pilot creature token with "This token crews Vehicles as though its power were 2 greater."
Crew 8 (Tap any number of creatures you control with total power 8 or more: This Vehicle becomes an artifact creature until end of turn.)
Shorikai, Genesis Engine can be your commander.

Martial Coup

Create X 1/1 white Soldier creature tokens. If X is 5 or more, destroy all other creatures.

Thalisse, Reverent Medium

At the beginning of each end step, create X 1/1 white Spirit creature tokens with flying, where X is the number of tokens you created this turn.

Marsh Flats

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. This artifact deals 1 damage to you.

Thunderhawk Gunship

Flying
When this Vehicle enters, create two 2/2 white Astartes Warrior creature tokens with vigilance.
Whenever this Vehicle attacks, attacking creatures you control gain flying until end of turn.
Crew 2

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
This artifact enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on this artifact.

Swamp

Rootborn Defenses

Populate. Creatures you control gain indestructible until end of turn. (To populate, create a token that's a copy of a creature token you control.)

Cavern of Souls

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Launch the Fleet

Strive — This spell costs {1} more to cast for each target beyond the first.
Until end of turn, any number of target creatures each gain "Whenever this creature attacks, create a 1/1 white Soldier creature token that's tapped and attacking."

Callidus Assassin

Flash
Polymorphine — You may have this creature enter tapped as a copy of any creature on the battlefield, except it has "When this creature enters, destroy up to one other target creature with the same name as this creature."

Godless Shrine

({T}: Add {W} or {B}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Anointed Procession

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Shipwreck Marsh

This land enters tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Hour of Reckoning

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy all nontoken creatures.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Thunderwolf Cavalry

First strike
Crushing Teeth — Whenever this creature deals combat damage to a player, put a +1/+1 counter on each other creature you control.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Epistolary Librarian

Veil of Time — Whenever this creature attacks, you may cast a spell with mana value X or less from your hand without paying its mana cost, where X is the number of attacking creatures.

Thran Dynamo

Inquisitorial Rosette

Inquisition Agents — Whenever equipped creature attacks, create a 2/2 white Astartes Warrior creature token with vigilance that's attacking. Then attacking creatures gain menace until end of turn.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Primaris Chaplain

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
Rosarius — Whenever this creature attacks, it gains indestructible until end of turn.

Watery Grave

({T}: Add {U} or {B}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Underground Sea

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Marneus Calgar

Double strike
Master Tactician — Whenever one or more tokens you control enter, draw a card.
Chapter Master — {6}: Create two 2/2 white Astartes Warrior creature tokens with vigilance.

Vanguard Suppressor

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Flying
Suppressing Fire — Whenever this creature deals combat damage to a player, draw a card.

Arcane Sanctum

This land enters tapped.
{T}: Add {W}, {U}, or {B}.

Flooded Strand

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Deny the Witch

Counter target spell, activated ability, or triggered ability. Its controller loses life equal to the number of creatures you control.

Company Commander

Command Section — When this creature enters, create a number of 1/1 white Soldier creature tokens equal to the number of opponents you have.
Bring it Down! — Whenever this creature attacks, creatures you control gain deathtouch until end of turn.

Anguished Unmaking

Exile target nonland permanent. You lose 3 life.

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Sea of Clouds

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Collective Effort

Escalate—Tap an untapped creature you control. (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Destroy target creature with power 4 or greater.
• Destroy target enchantment.
• Put a +1/+1 counter on each creature target player controls.

Inquisitor Greyfax

Vigilance
Unquestionable Wisdom — Other creatures you control get +1/+0 and have vigilance.
Hunt for Heresy — {1}, {T}: Tap target creature an opponent controls. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

And They Shall Know No Fear

Choose a creature type. Creatures you control of the chosen type get +1/+0 and gain indestructible until end of turn.

Deserted Beach

This land enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Island

Command Tower

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

Rabble Rousing

Hideaway 5 (When this enchantment enters, look at the top five cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Whenever you attack with one or more creatures, create that many 1/1 green and white Citizen creature tokens. Then if you control ten or more creatures, you may play the exiled card without paying its mana cost.

Protect the Negotiators

Kicker {W} (You may pay an additional {W} as you cast this spell.)
If this spell was kicked, create a 1/1 white Soldier creature token.
Counter target spell unless its controller pays {1} for each creature you control.

Locus of Enlightenment

Locus of Enlightenment has each activated ability of the exiled cards used to craft it. You may activate each of those abilities only once each turn.
Whenever you activate an ability that isn't a mana ability, copy it. You may choose new targets for the copy.

The Enigma Jewel

The Enigma Jewel enters tapped.
{T}: Add {C}{C}. Spend this mana only to activate abilities.
Craft with four or more nonlands with activated abilities {8}{U} ({8}{U}, Exile this artifact, Exile the four or more from among other permanents you control and/or cards in your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

The Enigma Jewel // Locus of Enlightenment

Thought Vessel

Irenicus's Vile Duplication

Create a token that's a copy of target creature you control, except the token has flying and it isn't legendary.

Eiganjo, Seat of the Empire

{T}: Add {W}.
Channel — {2}{W}, Discard this card: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

Ultramarines Honour Guard

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Other creatures you control get +1/+1.

Takenuma, Abandoned Mire

{T}: Add {B}.
Channel — {3}{B}, Discard this card: Mill three cards, then return a creature or planeswalker card from your graveyard to your hand. This ability costs {1} less to activate for each legendary creature you control.

Belisarius Cawl

Ultima Founding — {T}, Tap two untapped artifacts you control: Create a 2/2 white Astartes Warrior creature token with vigilance.
Master of Machines — {T}, Tap X untapped creatures you control: Look at the top X cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Vexilus Praetor

Flash
Vigilance
Aegis of the Emperor — Commanders you control have protection from everything.

Birth of the Imperium

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 2/2 white Astartes Warrior creature token with vigilance for each opponent you have.
II — Each opponent sacrifices a creature of their choice.
III — Draw two cards for each opponent who controls fewer creatures than you.

Collector's Vault

{2}, {T}: Draw a card, then discard a card. Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Shattered Sanctum

This land enters tapped unless you control two or more other lands.
{T}: Add {W} or {B}.

Mimic Vat

Imprint — Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with this artifact to its owner's graveyard.
{3}, {T}: Create a token that's a copy of a card exiled with this artifact. It gains haste. Exile it at the beginning of the next end step.

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Primaris Eliminator

When this creature enters, choose one —
• Executioner Round — Destroy target creature.
• Hyperfrag Round — Creatures target player controls get -2/-2 until end of turn.

Arcane Signet

Myriad Landscape

This land enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice this land: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Vault of Champions

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Vault of the Archangel

{T}: Add {C}.
{2}{W}{B}, {T}: Creatures you control gain deathtouch and lifelink until end of turn.

Path of Ancestry

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Defenders of Humanity

When this enchantment enters, create X 2/2 white Astartes Warrior creature tokens with vigilance.
{X}{2}{W}, Exile this enchantment: Create X 2/2 white Astartes Warrior creature tokens with vigilance. Activate only if you control no creatures and only during your turn.

Worn Powerstone

This artifact enters tapped.
{T}: Add {C}{C}.

Space Marine Devastator

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Grav-cannon — When this creature enters, destroy up to one target artifact or enchantment.

Deploy to the Front

Create X 1/1 white Soldier creature tokens, where X is the number of creatures on the battlefield.

Grand Crescendo

Create X 1/1 green and white Citizen creature tokens. Creatures you control gain indestructible until end of turn.

Tundra

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. This artifact deals 1 damage to you.

Darkwater Catacombs

Scrubland

Minas Tirith

Minas Tirith enters tapped unless you control a legendary creature.
{T}: Add {W}.
{1}{W}, {T}: Draw a card. Activate only if you attacked with two or more creatures this turn.

Morphic Pool

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Basalt Monolith

This artifact doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{3}: Untap this artifact.

Commissar Severina Raine

Leading from the Front — Whenever Commissar Severina Raine attacks, each opponent loses X life, where X is the number of other attacking creatures.
Summary Execution — {2}, Sacrifice another creature: You gain 2 life and draw a card.

Entrapment Maneuver

Target player sacrifices an attacking creature of their choice. You create X 1/1 white Soldier creature tokens, where X is that creature's toughness.

Talisman of Hierarchy

{T}: Add {C}.
{T}: Add {W} or {B}. This artifact deals 1 damage to you.

Halo Fountain

{W}, {T}, Untap a tapped creature you control: Create a 1/1 green and white Citizen creature token.
{W}{W}, {T}, Untap two tapped creatures you control: Draw a card.
{W}{W}{W}{W}{W}, {T}, Untap fifteen tapped creatures you control: You win the game.

Skycloud Expanse

Sicarian Infiltrator

Flash
Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Benediction of the Omnissiah — When this creature enters, draw a card.

Search the Premises

Whenever a creature attacks you or a planeswalker you control, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Castle Ardenvale

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

Plains

Fell the Mighty

Destroy all creatures with power greater than target creature's power.

Mortify

Monologue Tax

Whenever an opponent casts their second spell each turn, you create a Treasure token.

The Golden Throne

Arcane Life-support — If you would lose the game, instead exile The Golden Throne and your life total becomes 1.
A Thousand Souls Die Every Day — {T}, Sacrifice a creature: Add three mana in any combination of colors.