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.

Flayer of the Hatebound

Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)
Whenever Flayer of the Hatebound or another creature enters from your graveyard, that creature deals damage equal to its power to any target.

Goblin Assassin

Whenever Goblin Assassin or another Goblin enters, each player flips a coin. Each player whose coin comes up tails sacrifices a creature.

Jinxed Ring

Whenever a nontoken permanent is put into your graveyard from the battlefield, Jinxed Ring deals 1 damage to you.
Sacrifice a creature: Target opponent gains control of Jinxed Ring. (This effect lasts indefinitely.)

Goblin Grenade

As an additional cost to cast this spell, sacrifice a Goblin.
Goblin Grenade deals 5 damage to any target.

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.)

Bloodshot Cyclops

{T}, Sacrifice a creature: Bloodshot Cyclops deals damage equal to the sacrificed creature's power to any target.

Skirk Prospector

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.

Trading Post

{1}, {T}, Discard a card: You gain 4 life.
{1}, {T}, Pay 1 life: Create a 0/1 white Goat creature token.
{1}, {T}, Sacrifice a creature: Return target artifact card from your graveyard to your hand.
{1}, {T}, Sacrifice an artifact: Draw a card.

Blasphemous Act

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

Thud

As an additional cost to cast this spell, sacrifice a creature.
Thud deals damage equal to the sacrificed creature's power to any target.

Squee, the Immortal

You may cast Squee, the Immortal from your graveyard or from exile.

Burning Vengeance

Whenever you cast a spell from your graveyard, Burning Vengeance deals 2 damage to any target.

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}

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Hour of Devastation

All creatures lose indestructible until end of turn. Hour of Devastation deals 5 damage to each creature and each non-Bolas planeswalker.

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Blackblade Reforged

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

Hellion Eruption

Sacrifice all creatures you control, then create that many 4/4 red Hellion creature tokens.

Endless Atlas

{2}, {T}: Draw a card. Activate only if you control three or more lands with the same name.

Desecrated Tomb

Whenever one or more creature cards leave your graveyard, create a 1/1 black Bat creature token with flying.

Sol Ring

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Ricochet Trap

If an opponent cast a blue spell this turn, you may pay {R} rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Volcanic Vision

Return target instant or sorcery card from your graveyard to your hand. Volcanic Vision deals damage equal to that card's mana value to each creature your opponents control. Exile Volcanic Vision.

Shenanigans

Destroy target artifact.
Dredge 1 (If you would draw a card, you may mill a card instead. If you do, return this card from your graveyard to your hand.)

Shivan Harvest

{1}{R}, Sacrifice a creature: Destroy target nonbasic land.

Jhoira's Familiar

Flying
Historic spells you cast cost {1} less to cast. (Artifacts, legendaries, and Sagas are historic.)

Tormenting Voice

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

Blood Moon

Fire Diamond

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

Goblin Warchief

Goblin spells you cast cost {1} less to cast.
Goblins you control have haste.

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Hazoret's Monument

Red creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, you may discard a card. If you do, draw a card.

Runaway Steam-Kin

Whenever you cast a red spell, if Runaway Steam-Kin has fewer than three +1/+1 counters on it, put a +1/+1 counter on Runaway Steam-Kin.
Remove three +1/+1 counters from Runaway Steam-Kin: Add {R}{R}{R}.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Loxodon Warhammer

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

Pyroblast

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

Carnage Altar

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.

Airdrop Condor

Flying
{1}{R}, Sacrifice a Goblin creature: Airdrop Condor deals damage equal to the sacrificed creature's power to any target.

Stolen Strategy

At the beginning of your upkeep, exile the top card of each opponent's library. Until end of turn, you may cast spells from among those exiled cards, and you may spend mana as though it were mana of any color to cast those spells.

Goblin Trashmaster

Other Goblins you control get +1/+1.
Sacrifice a Goblin: Destroy target artifact.

Boggart Shenanigans

Whenever another Goblin you control is put into a graveyard from the battlefield, you may have Boggart Shenanigans deal 1 damage to target player or planeswalker.

Heirloom Blade

Equipped creature gets +3/+1.
Whenever equipped creature dies, you may reveal cards from the top of your library until you reveal a creature card that shares a creature type with it. Put that card into your hand and the rest on the bottom of your library in a random order.
Equip {1}

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Rogue's Gloves

Whenever equipped creature deals combat damage to a player, you may draw a card.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Jinxed Idol

At the beginning of your upkeep, Jinxed Idol deals 2 damage to you.
Sacrifice a creature: Target opponent gains control of Jinxed Idol.

Mountain

Chain Reaction

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

Pashalik Mons

Whenever Pashalik Mons or another Goblin you control dies, Pashalik Mons deals 1 damage to any target.
{3}{R}, Sacrifice a Goblin: Create two 1/1 red Goblin creature tokens.

Staff of Nin

At the beginning of your upkeep, draw a card.
{T}: Staff of Nin deals 1 damage to any target.

Red Elemental Blast

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

Ring of Valkas

Equipped creature has haste. (It can attack and {T} no matter when it came under your control.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's red.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Hero's Blade

Equipped creature gets +3/+2.
Whenever a legendary creature you control enters, you may attach Hero's Blade to it.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Skyfire Phoenix

Flying, haste
When you cast your commander, return Skyfire Phoenix from your graveyard to the battlefield.

Thermopod

{S}: Thermopod gains haste until end of turn. ({S} can be paid with one mana from a snow source.)
Sacrifice a creature: Add {R}.

Squee, Goblin Nabob

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

Goblin Chirurgeon

Sacrifice a Goblin: Regenerate target creature.

Mind Stone

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

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.