Behold the Multiverse

Scry 2, then draw two cards.
Foretell {1}{U} (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.)

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

Spark Double

You may have Spark Double enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Nevinyrral's Disk

Nevinyrral's Disk enters tapped.
{1}, {T}: Destroy all artifacts, creatures, and enchantments.

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Izzet Signet

Monastery Siege

As Monastery Siege enters, choose Khans or Dragons.
• Khans — At the beginning of your draw step, draw an additional card, then discard a card.
• Dragons — Spells your opponents cast that target you or a permanent you control cost {2} more to cast.

Tunneling Geopede

Landfall — Whenever a land you control enters, Tunneling Geopede deals 1 damage to each opponent.

Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Tectonic Hazard

Tectonic Hazard deals 1 damage to each opponent and each creature they control.

Immolation Shaman

Whenever an opponent activates an ability of an artifact, creature, or land that isn't a mana ability, Immolation Shaman deals 1 damage to that player.
{3}{R}{R}: Immolation Shaman gets +3/+3 and gains menace until end of turn.

Caltrops

Whenever a creature attacks, Caltrops deals 1 damage to it.

Pull from Tomorrow

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

You Find the Villains' Lair

Choose one —
• Foil Their Scheme — Counter target spell.
• Learn Their Secrets — Draw two cards, then discard two cards.

Basilisk Collar

Equipped creature has deathtouch and lifelink.
Equip {2}

Arcane Signet

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

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Ghyrson Starn, Kelermorph

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Three Autostubs — Whenever another source you control deals exactly 1 damage to a permanent or player, Ghyrson Starn, Kelermorph deals 2 damage to that permanent or player.

Firebrand Archer

Whenever you cast a noncreature spell, Firebrand Archer deals 1 damage to each opponent.

Spitfire Lagac

Landfall — Whenever a land you control enters, Spitfire Lagac deals 1 damage to each opponent.

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Lobber Crew

Defender
{T}: Lobber Crew deals 1 damage to each opponent.
Whenever you cast a multicolored spell, untap Lobber Crew.

Spikefield Cave

Spikefield Cave enters tapped.
{T}: Add {R}.

Spikefield Hazard

Spikefield Hazard deals 1 damage to any target. If a permanent dealt damage this way would die this turn, exile it instead.

Spikefield Hazard // Spikefield Cave

Burning Earth

Whenever a player taps a nonbasic land for mana, Burning Earth deals 1 damage to that player.

Sunscorched Desert

When Sunscorched Desert enters, it deals 1 damage to target player or planeswalker.
{T}: Add {C}.

Witty Roastmaster

Alliance — Whenever another creature you control enters, Witty Roastmaster deals 1 damage to each opponent.

Circle of Flame

Whenever a creature without flying attacks you or a planeswalker you control, Circle of Flame deals 1 damage to that creature.

Smash to Dust

Choose one —
• Destroy target artifact.
• Destroy target creature with defender.
• Smash to Dust deals 1 damage to each creature your opponents control.

Electrostatic Field

Defender
Whenever you cast an instant or sorcery spell, Electrostatic Field deals 1 damage to each opponent.

Cathartic Reunion

As an additional cost to cast this spell, discard two cards.
Draw three cards.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Butcher's Cleaver

Equipped creature gets +3/+0.
As long as equipped creature is a Human, it has lifelink.
Equip {3}

Hissing Iguanar

Whenever another creature dies, you may have Hissing Iguanar deal 1 damage to target player or planeswalker.

Negate

Steam Vents

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

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.

Outpost Siege

As Outpost Siege enters, choose Khans or Dragons.
• Khans — At the beginning of your upkeep, exile the top card of your library. Until end of turn, you may play that card.
• Dragons — Whenever a creature you control leaves the battlefield, Outpost Siege deals 1 damage to any target.

Temple of Epiphany

Temple of Epiphany enters tapped.
When Temple of Epiphany enters, scry 1.
{T}: Add {U} or {R}.

Dagger Caster

When Dagger Caster enters, it deals 1 damage to each opponent and 1 damage to each creature your opponents control.

Gelectrode

{T}: Gelectrode deals 1 damage to any target.
Whenever you cast an instant or sorcery spell, you may untap Gelectrode.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Niv-Mizzet, the Firemind

Flying
Whenever you draw a card, Niv-Mizzet, the Firemind deals 1 damage to any target.
{T}: Draw a card.

Maestros Theater

When Maestros Theater enters, sacrifice it. When you do, search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Kessig Flamebreather

Whenever you cast a noncreature spell, Kessig Flamebreather deals 1 damage to each opponent.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Quietus Spike

Equipped creature has deathtouch.
Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.
Equip {3}

Unexpected Windfall

Mind Stone

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

Fellwar Stone

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Blisterspit Gremlin

{1}, {T}: Blisterspit Gremlin deals 1 damage to each opponent.
Whenever you cast a noncreature spell, untap Blisterspit Gremlin.

Spear Spewer

Defender
{T}: Spear Spewer deals 1 damage to each player.

Coldsteel Heart

Coldsteel Heart enters tapped.
As Coldsteel Heart enters, choose a color.
{T}: Add one mana of the chosen color.

Spiteful Prankster

During your turn, Spiteful Prankster has first strike.
Whenever another creature dies, Spiteful Prankster deals 1 damage to target player or planeswalker.

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. Talisman of Creativity deals 1 damage to you.

Electrickery

Electrickery deals 1 damage to target creature you don't control.
Overload {1}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Concentrate

Shivan Gorge

{T}: Add {C}.
{2}{R}, {T}: Shivan Gorge deals 1 damage to each opponent.

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Blazing Volley

Blazing Volley deals 1 damage to each creature your opponents control.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Gorgon's Head

Equipped creature has deathtouch.
Equip {2}

Command Tower

Corrupted Conscience

Enchant creature
You control enchanted creature.
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Aether Gale

Return six target nonland permanents to their owners' hands.

Desert

{T}: Add {C}.
{T}: Desert deals 1 damage to target attacking creature. Activate only during the end of combat step.

Tandem Lookout

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Tandem Lookout is paired with another creature, each of those creatures has "Whenever this creature deals damage to an opponent, draw a card."

Ash Barrens

{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.)

Island

Myriad Landscape

Myriad Landscape enters 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.

Brimstone Trebuchet

Defender, reach
{T}: Brimstone Trebuchet deals 1 damage to each opponent.
Whenever a Knight you control enters, untap Brimstone Trebuchet.

Nettle Drone

Devoid (This card has no color.)
{T}: Nettle Drone deals 1 damage to each opponent.
Whenever you cast a colorless spell, untap Nettle Drone.

Mountain

Sakashima the Impostor

You may have Sakashima the Impostor enter as a copy of any creature on the battlefield, except its name is Sakashima the Impostor, it's legendary in addition to its other types, and it has "{2}{U}{U}: Return this creature to its owner's hand at the beginning of the next end step."