Delighted Halfling

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell, and that spell can't be countered.

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Chain of Vapor

Return target nonland permanent to its owner's hand. Then that permanent's controller may sacrifice a land of their choice. If the player does, they may copy this spell and may choose a new target for that copy.

Mithril Coat

Flash
Indestructible
When Mithril Coat enters, attach it to target legendary creature you control.
Equipped creature has indestructible.
Equip {3}

Winged Boots

Equipped creature has flying and ward {4}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
Equip {1}

Wooded Foothills

{T}, Pay 1 life, Sacrifice Wooded Foothills: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Flooded Strand

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

Tyvar's Stand

Target creature you control gets +X/+X and gains hexproof and indestructible until end of turn. (A creature with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Misty Rainforest

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

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Rashmi, Eternities Crafter

Whenever you cast your first spell each turn, reveal the top card of your library. You may cast it without paying its mana cost if it's a spell with lesser mana value. If you don't cast it, put it into your hand.

Oracle of Mul Daya

You may play an additional land on each of your turns.
Play with the top card of your library revealed.
You may play lands from the top of your library.

Scourge of the Throne

Flying
Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Whenever Scourge of the Throne attacks for the first time each turn, if it's attacking the player with the most life or tied for most life, untap all attacking creatures. After this phase, there is an additional combat phase.

Windswept Heath

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

Elvish Mystic

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
Ketria Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Neheb, the Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
At the beginning of each of your postcombat main phases, add {R} for each 1 life your opponents have lost this turn.

Scalding Tarn

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

Mountain

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Fyndhorn Elves

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Dockside Extortionist

When Dockside Extortionist enters, create X Treasure tokens, where X is the number of artifacts and enchantments your opponents control. (Treasure tokens are artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Birds of Paradise

Counterspell

Negate

Champion's Helm

Equipped creature gets +2/+2.
As long as equipped creature is legendary, it has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Pako, Arcane Retriever

Partner with Haldan, Avid Arcanist
Haste
Whenever Pako, Arcane Retriever attacks, exile the top card of each player's library and put a fetch counter on each of them. Put a +1/+1 counter on Pako for each noncreature card exiled this way.

Island

Timetwister

Each player shuffles their hand and graveyard into their library, then draws seven cards. (Then put Timetwister into its owner's graveyard.)

The Reaver Cleaver

Equipped creature gets +1/+1 and has trample and "Whenever this creature deals combat damage to a player or planeswalker, create that many Treasure tokens."
Equip {3}

Sol Ring

Shattering Spree

Replicate {R} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Destroy target artifact.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Bear Umbra

Enchant creature
Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Wheel of Fortune

Each player discards their hand, then draws seven cards.

Aggravated Assault

{3}{R}{R}: Untap all creatures you control. After this main phase, there is an additional combat phase followed by an additional main phase. Activate only as a sorcery.

Escape to the Wilds

Exile the top five cards of your library. You may play cards exiled this way until the end of your next turn.
You may play an additional land this turn.

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Forest

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Bloodstained Mire

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

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Azusa, Lost but Seeking

You may play two additional lands on each of your turns.

Mizzium Mortars

Mizzium Mortars deals 4 damage to target creature you don't control.
Overload {3}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Volcanic Island

Polluted Delta

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

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Arbor Elf

Kodama's Reach

Command Tower

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

Steam Vents

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

Sword of Feast and Famine

Equipped creature gets +2/+2 and has protection from black and from green.
Whenever equipped creature deals combat damage to a player, that player discards a card and you untap all lands you control.
Equip {2}

Yavimaya, Cradle of Growth

Each land is a Forest in addition to its other land types.

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Karlach, Fury of Avernus

Whenever you attack, if it's the first combat phase of the turn, untap all attacking creatures. They gain first strike until end of turn. After this phase, there is an additional combat phase.
Choose a Background (You can have a Background as a second commander.)

Haldan, Avid Arcanist

Partner with Pako, Arcane Retriever (When this creature enters, target player may put Pako into their hand from their library, then shuffle.)
You may play lands and cast noncreature spells from among cards you exiled that have fetch counters on them, and you may spend mana as though it were mana of any color to cast those spells.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Breeding Pool

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

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Taiga

Arid Mesa

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

Tropical Island

Entish Restoration

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle. If you control a creature with power 4 or greater, instead search your library for up to three basic land cards, put them onto the battlefield tapped, then shuffle.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Bloom Tender

{T}: For each color among permanents you control, add one mana of that color.

Verdant Catacombs

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

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.