Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Valakut, the Molten Pinnacle

Valakut, the Molten Pinnacle enters tapped.
Whenever a Mountain you control enters, if you control at least five other Mountains, you may have Valakut, the Molten Pinnacle deal 3 damage to any target.
{T}: Add {R}.

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.")

Arena

{3}, {T}: Tap target creature you control and target creature of an opponent's choice they control. Those creatures fight each other. (Each deals damage equal to its power to the other.)

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Gratuitous Violence

If a creature you control would deal damage to a permanent or player, it deals double that damage instead.

Kuldotha Phoenix

Flying, haste
Metalcraft — {4}: Return Kuldotha Phoenix from your graveyard to the battlefield. Activate only during your upkeep and only if you control three or more artifacts.

Madcap Skills

Enchant creature
Enchanted creature gets +3/+0 and has menace.

Crooked Scales

{4}, {T}: Flip a coin. If you win the flip, destroy target creature an opponent controls. If you lose the flip, destroy target creature you control unless you pay {3} and repeat this process.

Uncaged Fury

Target creature gets +1/+1 and gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Fire Diamond

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

Amok

{1}, Discard a card at random: Put a +1/+1 counter on target creature.

Fiery Confluence

Choose three. You may choose the same mode more than once.
• Fiery Confluence deals 1 damage to each creature.
• Fiery Confluence deals 2 damage to each opponent.
• Destroy target artifact.

Terrain Generator

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

Arcane Lighthouse

{T}: Add {C}.
{1}, {T}: Until end of turn, creatures your opponents control lose hexproof and shroud and can't have hexproof or shroud.

Death Spark

Death Spark deals 1 damage to any target.
At the beginning of your upkeep, if Death Spark is in your graveyard with a creature card directly above it, you may pay {1}. If you do, return Death Spark to your hand.

Mind Stone

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

Immolation

Enchant creature
Enchanted creature gets +2/-2.

Cathartic Reunion

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

Tilonalli's Crown

Enchant creature
When Tilonalli's Crown enters, it deals 1 damage to enchanted creature.
Enchanted creature gets +3/+0 and has trample.

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Knollspine Invocation

{X}, Discard a card with mana value X: Knollspine Invocation deals X damage to any target.

Inquisitor's Flail

If equipped creature would deal combat damage, it deals double that damage instead.
If another creature would deal combat damage to equipped creature, it deals double that damage to equipped creature instead.
Equip {2}

Bearer of the Heavens

When Bearer of the Heavens dies, destroy all permanents at the beginning of the next end step.

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.")

Oracle's Vault

{2}, {T}: Exile the top card of your library. Until end of turn, you may play that card. Put a brick counter on Oracle's Vault.
{T}: Exile the top card of your library. Until end of turn, you may play that card without paying its mana cost. Activate only if there are three or more brick counters on Oracle's Vault.

Eternal Warrior

Enchant creature
Enchanted creature has vigilance.

Furnace of Rath

If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Uba Mask

If a player would draw a card, that player exiles that card face up instead.
Each player may play lands and cast spells from among cards they exiled with Uba Mask this turn.

Savage Beating

Cast this spell only during your turn and only during combat.
Choose one —
• Creatures you control gain double strike until end of turn.
• Untap all creatures you control. After this phase, there is an additional combat phase.
Entwine {1}{R} (Choose both if you pay the entwine cost.)

Pyrohemia

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pyrohemia.
{R}: Pyrohemia deals 1 damage to each creature and each player.

Sea Gate Wreckage

{T}: Add {C}. ({C} represents colorless mana.)
{2}{C}, {T}: Draw a card. Activate only if you have no cards in hand.

Words of War

{1}: The next time you would draw a card this turn, Words of War deals 2 damage to any target instead.

Mindless Automaton

Mindless Automaton enters with two +1/+1 counters on it.
{1}, Discard a card: Put a +1/+1 counter on Mindless Automaton.
Remove two +1/+1 counters from Mindless Automaton: Draw a card.

Embercleave

Flash
This spell costs {1} less to cast for each attacking creature you control.
When Embercleave enters, attach it to target creature you control.
Equipped creature gets +1/+1 and has double strike and trample.
Equip {3}

Wrecking Ogre

Double strike
Bloodrush — {3}{R}{R}, Discard Wrecking Ogre: Target attacking creature gets +3/+3 and gains double strike until end of turn.

Fiendlash

Equipped creature gets +2/+0 and has reach.
Whenever equipped creature is dealt damage, it deals damage equal to its power to target player or planeswalker.
Equip {2}{R}

Pyrewild Shaman

Bloodrush — {1}{R}, Discard Pyrewild Shaman: Target attacking creature gets +3/+1 until end of turn.
Whenever one or more creatures you control deal combat damage to a player, if Pyrewild Shaman is in your graveyard, you may pay {3}. If you do, return Pyrewild Shaman to your hand.

Hazoret the Fervent

Indestructible, haste
Hazoret the Fervent can't attack or block unless you have one or fewer cards in hand.
{2}{R}, Discard a card: Hazoret deals 2 damage to each opponent.

Flamewake Phoenix

Flying, haste
This creature attacks each combat if able.
At the beginning of combat on your turn, if you control a creature with power 4 or greater, you may pay {R}. If you do, return this card from your graveyard to the battlefield.

Squee, Goblin Nabob

At the beginning of your upkeep, you may return Squee, Goblin Nabob from your graveyard to your hand.

Nahiri's Wrath

As an additional cost to cast this spell, discard X cards.
Nahiri's Wrath deals damage equal to the total mana value of the discarded cards to each of up to X target creatures and/or planeswalkers.

Loxodon Warhammer

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

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Avaricious Dragon

Flying
At the beginning of your draw step, draw an additional card.
At the beginning of your end step, discard your hand.

Key to the City

{T}, Discard a card: Up to one target creature can't be blocked this turn.
Whenever Key to the City becomes untapped, you may pay {2}. If you do, draw a card.

Mountain

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

O-Naginata

O-Naginata can be attached only to a creature with power 3 or greater.
Equipped creature gets +3/+0 and has trample.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Ruby Medallion

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

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Pyromancy

{3}, Discard a card at random: Pyromancy deals damage to any target equal to the mana value of the discarded card.

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Grafted Skullcap

At the beginning of your draw step, draw an additional card.
At the beginning of your end step, discard your hand.

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.

Stranglehold

Your opponents can't search libraries.
If an opponent would begin an extra turn, that player skips that turn instead.

Seize the Day

Untap target creature. After this main phase, there is an additional combat phase followed by an additional main phase.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Angrath's Marauders

If a source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Strata Scythe

Imprint — When Strata Scythe enters, search your library for a land card, exile it, then shuffle.
Equipped creature gets +1/+1 for each land on the battlefield with the same name as the exiled card.
Equip {3}

Null Brooch

{2}, {T}, Discard your hand: Counter target noncreature spell.

Pariah's Shield

All damage that would be dealt to you is dealt to equipped creature instead.
Equip {3}

Vow of Lightning

Enchant creature
Enchanted creature gets +2/+2, has first strike, and can't attack you or planeswalkers you control.

Dictate of the Twin Gods

Flash
If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Gustha's Scepter

{T}: Exile a card from your hand face down. You may look at it for as long as it remains exiled.
{T}: Return a card you own exiled with Gustha's Scepter to your hand.
When you lose control of Gustha's Scepter, put all cards exiled with Gustha's Scepter into their owner's graveyard.

Sol Ring

Tenza, Godo's Maul

Equipped creature gets +1/+1. As long as it's legendary, it gets an additional +2/+2. As long as it's red, it has trample.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

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}

Overblaze

Each time target permanent would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.
Splice onto Arcane {2}{R}{R} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.