Put a +1/+1 counter on target creature you control if it's legendary. Then it fights target creature an opponent controls. (Each deals damage equal to its power to the other.)
{2}
Arcane Signet
Artifact
{T}: Add one mana of any color in your commander's color identity.
{4}{W}{W}
Archon of Coronation
Creature - Archon
Flying
When Archon of Coronation enters the battlefield, you become the monarch.
As long as you're the monarch, damage doesn't cause you to lose life. (When a creature deals combat damage to you, its controller still becomes the monarch.)
5 /
5
--
Arctic Treeline
Snow Land - Forest Plains
({T}: Add {G} or {W}.)
Arctic Treeline enters the battlefield tapped.
{R}{G}
Arni Slays the Troll
Enchantment - Saga
(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I -- Target creature you control fights up to one target creature you don't control.
II -- Add {R}. Put two +1/+1 counters on up to one target creature you control.
III -- You gain life equal to the greatest power among creatures you control.
--
Ash Barrens
Land
{T}: Add {C}.
Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)
{2}{W}{W}
Baird, Steward of Argive
Legendary Creature - Human Soldier
Vigilance
Creatures can't attack you or planeswalkers you control unless their controller pays {1} for each of those creatures.
2 /
4
{2}{G}
Bala Ged Recovery
Sorcery
Return target card from your graveyard to your hand.
--
Bala Ged Sanctuary
Land
Bala Ged Sanctuary enters the battlefield tapped.
{T}: Add {G}.
{3}{G}{G}
Battle Mammoth
Creature - Elephant
Trample
Whenever a permanent you control becomes the target of a spell or ability an opponent controls, you may draw a card.
Foretell {2}{G}{G} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)
6 /
5
{2}
Blackblade Reforged
Legendary Artifact - Equipment
Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}
{8}{R}
Blasphemous Act
Sorcery
This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.
--
Boros Garrison
Land
Boros Garrison enters the battlefield tapped.
When Boros Garrison enters the battlefield, return a land you control to its owner's hand.
{T}: Add {R}{W}.
{R/W}{R/W}{R/W}
Boros Reckoner
Creature - Minotaur Wizard
Whenever Boros Reckoner is dealt damage, it deals that much damage to any target.
{R/W}: Boros Reckoner gains first strike until end of turn.
3 /
3
{4}{R}
Brash Taunter
Creature - Goblin
Indestructible
Whenever Brash Taunter is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: Brash Taunter fights another target creature.
1 /
1
--
Bretagard Stronghold
Land
Bretagard Stronghold enters the battlefield tapped.
{T}: Add {G}.
{G}{W}{W}, {T}, Sacrifice Bretagard Stronghold: Put a +1/+1 counter on each of up to two target creatures you control. They gain vigilance and lifelink until end of turn. Activate only as a sorcery.
{3}{R}{R}
Burn Down the House
Sorcery
Choose one --
• Burn Down the House deals 5 damage to each creature and each planeswalker.
• Create three 1/1 red Devil creature tokens with "When this creature dies, it deals 1 damage to any target." They gain haste until end of turn.
--
Cabaretti Courtyard
Land
When Cabaretti Courtyard enters the battlefield, sacrifice it. When you do, search your library for a basic Mountain, Forest, or Plains card, put it onto the battlefield tapped, then shuffle and you gain 1 life.
{2}{R}{R}
Chain Reaction
Sorcery
Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.
--
Cinder Glade
Land - Mountain Forest
({T}: Add {R} or {G}.)
Cinder Glade enters the battlefield tapped unless you control two or more basic lands.
--
Command Tower
Land
{T}: Add one mana of any color in your commander's color identity.
{3}
Commander's Sphere
Artifact
{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.
{3}{R}{R}
Court of Ire
Enchantment
When Court of Ire enters the battlefield, you become the monarch.
At the beginning of your upkeep, Court of Ire deals 2 damage to any target. If you're the monarch, it deals 7 damage instead.
{3}{R}
Crimson Fleet Commodore
Creature - Ogre Pirate
Trample
When Crimson Fleet Commodore enters the battlefield, you become the monarch.
5 /
2
{2}{G}
Cultivate
Sorcery
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.
{G}{W}
Eladamri's Call
Instant
Search your library for a creature card, reveal that card, put it into your hand, then shuffle.
--
Elfhame Palace
Land
Elfhame Palace enters the battlefield tapped.
{T}: Add {G} or {W}.
{3}{R}
Emberwilde Captain
Creature - Djinn Pirate
When Emberwilde Captain enters the battlefield, you become the monarch.
Whenever an opponent attacks you while you're the monarch, Emberwilde Captain deals damage to that player equal to the number of cards in their hand.
4 /
2
{4}{G}
Entourage of Trest
Creature - Elf Soldier
When Entourage of Trest enters the battlefield, you become the monarch.
Entourage of Trest can block an additional creature each combat as long as you're the monarch.
4 /
4
{W}
Esper Sentinel
Artifact Creature - Human Soldier
Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.
1 /
1
--
Exotic Orchard
Land
{T}: Add one mana of any color that a land an opponent controls could produce.
{1}
Explorer's Scope
Artifact - Equipment
Whenever equipped creature attacks, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)
{G}
Fog
Instant
Prevent all combat damage that would be dealt this turn.
--
Forest
Basic Land - Forest
({T}: Add {G}.)
--
Forest
Basic Land - Forest
({T}: Add {G}.)
--
Forest
Basic Land - Forest
({T}: Add {G}.)
--
Forest
Basic Land - Forest
({T}: Add {G}.)
{W}
Gideon's Sacrifice
Instant
Choose a creature or planeswalker you control. All damage that would be dealt this turn to you and permanents you control is dealt to the chosen permanent instead (if it's still on the battlefield).
{R}{R}
Grenzo, Havoc Raiser
Legendary Creature - Goblin Rogue
Whenever a creature you control deals combat damage to a player, choose one --
• Goad target creature that player controls.
• Exile the top card of that player's library. Until end of turn, you may cast that card and you may spend mana as though it were mana of any color to cast that spell.
2 /
2
--
Gruul Turf
Land
Gruul Turf enters the battlefield tapped.
When Gruul Turf enters the battlefield, return a land you control to its owner's hand.
{T}: Add {R}{G}.
{4}{W}
Gustcloak Savior
Creature - Bird Soldier
Flying
Whenever a creature you control becomes blocked, you may untap that creature and remove it from combat.
3 /
4
{2}{G}
Harrow
Instant
As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.
{3}{R}{R}
Hour of Devastation
Sorcery
All creatures lose indestructible until end of turn. Hour of Devastation deals 5 damage to each creature and each non-Bolas planeswalker.
{2}{G}
Hunter's Insight
Instant
Choose target creature you control. Whenever that creature deals combat damage to a player or planeswalker this turn, draw that many cards.
{R}{G}{W}
Incandescent Aria
Sorcery
Incandescent Aria deals 3 damage to each nontoken creature.
{1}
Infiltration Lens
Artifact - Equipment
Whenever equipped creature becomes blocked by a creature, you may draw two cards.
Equip {1}
--
Inspiring Vantage
Land
Inspiring Vantage enters the battlefield tapped unless you control two or fewer other lands.
{T}: Add {R} or {W}.
{R}{G}{W}
Jared Carthalion, True Heir
Legendary Creature - Human Warrior
When Jared Carthalion, True Heir enters the battlefield, target opponent becomes the monarch. You can't become the monarch this turn.
If damage would be dealt to Jared Carthalion while you're the monarch, prevent that damage and put that many +1/+1 counters on it.
3 /
3
{2}{G}
Khalni Ambush
Instant
Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
--
Khalni Territory
Land
Khalni Territory enters the battlefield tapped.
{T}: Add {G}.
{2}{G}
Kodama's Reach
Sorcery - Arcane
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.
{3}{R}
Lavabrink Floodgates
Artifact
{T}: Add {R}{R}.
At the beginning of each player's upkeep, that player may put a doom counter on Lavabrink Floodgates or remove a doom counter from it. Then if it has three or more doom counters on it, sacrifice Lavabrink Floodgates. When you do, it deals 6 damage to each creature.
{2}
Lightning Greaves
Artifact - Equipment
Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}
{3}{W}
Loyal Unicorn
Creature - Unicorn
Vigilance
Lieutenant -- At the beginning of combat on your turn, if you control your commander, prevent all combat damage that would be dealt to creatures you control this turn. Other creatures you control gain vigilance until end of turn.
3 /
4
--
Mossfire Valley
Land
{1}, {T}: Add {R}{G}.
{W}
Mother of Runes
Creature - Human Cleric
{T}: Target creature you control gains protection from the color of your choice until end of turn.
1 /
1
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Mountain
Basic Land - Mountain
({T}: Add {R}.)
--
Myriad Landscape
Land
Myriad Landscape enters the battlefield tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.
{2}{G}
Myth Unbound
Enchantment
Your commander costs {1} less to cast for each time it's been cast from the command zone this game.
Whenever your commander is put into the command zone from anywhere, draw a card.
{1}{G}
Nature's Lore
Sorcery
Search your library for a Forest card, put that card onto the battlefield, then shuffle.
{2}{W}{W}
Palace Jailer
Creature - Human Soldier
When Palace Jailer enters the battlefield, you become the monarch.
When Palace Jailer enters the battlefield, exile target creature an opponent controls until an opponent becomes the monarch.
2 /
2
{2}{W}
Pariah
Enchantment - Aura
Enchant creature
All damage that would be dealt to you is dealt to enchanted creature instead.
--
Plains
Basic Land - Plains
({T}: Add {W}.)
--
Plains
Basic Land - Plains
({T}: Add {W}.)
--
Plains
Basic Land - Plains
({T}: Add {W}.)
{6}{G}{G}
Polyraptor
Creature - Dinosaur
Enrage -- Whenever Polyraptor is dealt damage, create a token that's a copy of Polyraptor.
5 /
5
{1}{G}
Prizefight
Instant
Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
{1}{G}
Rampant Growth
Sorcery
Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
{1}{G}
Regrowth
Sorcery
Return target card from your graveyard to your hand.
{1}{G}
Return to Nature
Instant
Choose one --
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.
{2}{G}{G}
Ripjaw Raptor
Creature - Dinosaur
Enrage -- Whenever Ripjaw Raptor is dealt damage, draw a card.
4 /
5
{G}{G}
Road of Return
Sorcery
Choose one --
• Return target permanent card from your graveyard to your hand.
• Put your commander into your hand from the command zone.
Entwine {2} (Choose both if you pay the entwine cost.)
--
Rootbound Crag
Land
Rootbound Crag enters the battlefield tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.
--
Rugged Highlands
Land
Rugged Highlands enters the battlefield tapped.
When Rugged Highlands enters the battlefield, you gain 1 life.
{T}: Add {R} or {G}.
{2}{G}{G}
Saryth, the Viper's Fang
Legendary Creature - Human Warlock
Other tapped creatures you control have deathtouch.
Other untapped creatures you control have hexproof.
{1}, {T}: Untap another target creature or land you control.
3 /
4
{1}{W}
Saving Grace
Enchantment - Aura
Flash
Enchant creature you control
When Saving Grace enters the battlefield, all damage that would be dealt this turn to you and permanents you control is dealt to enchanted creature instead.
Enchanted creature gets +0/+3.
--
Scattered Groves
Land - Forest Plains
({T}: Add {G} or {W}.)
Scattered Groves enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)
--
Selesnya Guildgate
Land - Gate
Selesnya Guildgate enters the battlefield tapped.
{T}: Add {G} or {W}.
--
Selesnya Sanctuary
Land
Selesnya Sanctuary enters the battlefield tapped.
When Selesnya Sanctuary enters the battlefield, return a land you control to its owner's hand.
{T}: Add {G}{W}.
{2}
Selesnya Signet
Artifact
{1}, {T}: Add {G}{W}.
{X}{R}{R}
Shatterskull Smashing
Sorcery
Shatterskull Smashing deals X damage divided as you choose among up to two target creatures and/or planeswalkers. If X is 6 or more, Shatterskull Smashing deals twice X damage divided as you choose among them instead.
--
Shatterskull, the Hammer Pass
Land
As Shatterskull, the Hammer Pass enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.
{T}: Add {R}.
{2}{G/W}
Shield of the Oversoul
Enchantment - Aura
Enchant creature
As long as enchanted creature is green, it gets +1/+1 and has indestructible. (Damage and effects that say "destroy" don't destroy it. If its toughness is 0 or less, it's still put into its owner's graveyard.)
As long as enchanted creature is white, it gets +1/+1 and has flying.
--
Shimmerdrift Vale
Snow Land
Shimmerdrift Vale enters the battlefield tapped.
As Shimmerdrift Vale enters the battlefield, choose a color.
{T}: Add one mana of the chosen color.
{5}{R}{R}
Skyline Despot
Creature - Dragon
Flying
When Skyline Despot enters the battlefield, you become the monarch.
At the beginning of your upkeep, if you're the monarch, create a 5/5 red Dragon creature token with flying.
5 /
5
{3}{G}
Skyshroud Claim
Sorcery
Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.
{W}
Soul Snare
Enchantment
{W}, Sacrifice Soul Snare: Exile target creature that's attacking you or a planeswalker you control.
{2}{R/W}{R/W}
Spitemare
Creature - Elemental
Whenever Spitemare is dealt damage, it deals that much damage to any target.
3 /
3
{5}{R}{R}
Star of Extinction
Sorcery
Destroy target land. Star of Extinction deals 20 damage to each creature and each planeswalker.
{X}{R}{R}
Starstorm
Instant
Starstorm deals X damage to each creature.
Cycling {3} ({3}, Discard this card: Draw a card.)
{2}{W}
Stormwild Capridor
Creature - Bird Goat
Flying
If noncombat damage would be dealt to Stormwild Capridor, prevent that damage. Put a +1/+1 counter on Stormwild Capridor for each 1 damage prevented this way.
1 /
3
--
Sunpetal Grove
Land
Sunpetal Grove enters the battlefield tapped unless you control a Forest or a Plains.
{T}: Add {G} or {W}.
{2}
Swiftfoot Boots
Artifact - Equipment
Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}
--
Temple of Abandon
Land
Temple of Abandon enters the battlefield tapped.
When Temple of Abandon enters the battlefield, scry 1.
{T}: Add {R} or {G}.
--
Temple of Plenty
Land
Temple of Plenty enters the battlefield tapped.
When Temple of Plenty enters the battlefield, scry 1.
{T}: Add {G} or {W}.
--
Temple of Triumph
Land
Temple of Triumph enters the battlefield tapped.
When Temple of Triumph enters the battlefield, scry 1.
{T}: Add {R} or {W}.
{1}{G}{G}
Thrashing Brontodon
Creature - Dinosaur
{1}, Sacrifice Thrashing Brontodon: Destroy target artifact or enchantment.
3 /
4
--
Throne of the High City
Land
{T}: Add {C}.
{4}, {T}, Sacrifice Throne of the High City: You become the monarch.
{G}
Worldly Tutor
Instant
Search your library for a creature card, reveal it, then shuffle and put the card on top.
{6}{R}{G}{W}
Zacama, Primal Calamity
Legendary Creature - Elder Dinosaur
Vigilance, reach, trample
When Zacama, Primal Calamity enters the battlefield, if you cast it, untap all lands you control.