Have

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Jaxis, the Troublemaker

{R}, {T}, Discard a card: Create a token that's a copy of another target creature you control. It gains haste and "When this token dies, draw a card." Sacrifice it at the beginning of the next end step. Activate only as a sorcery.
Blitz {1}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Razorkin Needlehead

This creature has first strike during your turn.
Whenever an opponent draws a card, this creature deals 1 damage to them.

Nibelheim Aflame

Choose target creature you control. It deals damage equal to its power to each other creature. If this spell was cast from a graveyard, discard your hand and draw four cards.
Flashback {5}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Unexpected Windfall

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 token: Add one mana of any color.")

Collector's Vault

{2}, {T}: Draw a card, then discard a card. Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Powerbalance

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, you may cast that card without paying its mana cost if the two spells have the same mana value.

Arcane Signet

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

Rubble Rouser

When this creature enters, you may discard a card. If you do, draw a card.
{T}, Exile a card from your graveyard: Add {R}. When you do, this creature deals 1 damage to each opponent.

Pirate's Pillage

Archetype of Aggression

Creatures you control have trample.
Creatures your opponents control lose trample and can't have or gain trample.

Elixir of Immortality

{2}, {T}: You gain 5 life. Shuffle this artifact and your graveyard into their owner's library.

Flashback

Target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Mana Geyser

Add {R} for each tapped land your opponents control.

Blade of Selves

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Equip {4}

Cavalier of Flame

{1}{R}: Creatures you control get +1/+0 and gain haste until end of turn.
When this creature enters, discard any number of cards, then draw that many cards.
When this creature dies, it deals X damage to each opponent and each planeswalker they control, where X is the number of land cards in your graveyard.

Thran Dynamo

Glint-Horn Buccaneer

Haste
Whenever you discard a card, this creature deals 1 damage to each opponent.
{1}{R}, Discard a card: Draw a card. Activate only if this creature is attacking.

Wheel of Misfortune

Each player secretly chooses a number 0 or greater, then all players reveal those numbers simultaneously and determine the highest and lowest numbers revealed this way. Wheel of Misfortune deals damage equal to the highest number to each player who chose that number. Each player who didn't choose the lowest number discards their hand, then draws seven cards.

Clive's Hideaway

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
{T}: Add {C}.
{2}, {T}: You may play the exiled card without paying its mana cost if you control four or more legendary creatures.

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.

The Fire Crystal

Red spells you cast cost {1} less to cast.
Creatures you control have haste.
{4}{R}{R}, {T}: Create a token that's a copy of target creature you control. Sacrifice it at the beginning of the next end step.

Bolt Bend

This spell costs {3} less to cast if you control a creature with power 4 or greater.
Change the target of target spell or ability with a single target.

Solemn Simulacrum

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

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Emeritus of Conflict

First strike
Whenever you cast your third spell each turn, this creature becomes prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)

Emeritus of Conflict // Lightning Bolt

Currency Converter

Whenever you discard a card, you may exile that card from your graveyard.
{2}, {T}: Draw a card, then discard a card.
{T}: Put a card exiled with this artifact into its owner's graveyard. If it's a land card, create a Treasure token. If it's a nonland card, create a 2/2 black Rogue creature token.

Mountain

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}

Goblin Welder

{T}: Choose target artifact a player controls and target artifact card in that player's graveyard. If both targets are still legal as this ability resolves, that player simultaneously sacrifices the artifact and returns the artifact card to the battlefield.

General Kreat, the Boltbringer

Whenever one or more Goblins you control attack, create a 1/1 red Goblin creature token that's tapped and attacking.
Whenever another creature you control enters, General Kreat deals 1 damage to each opponent.

Fanatic of Mogis

When this creature enters, it deals damage to each opponent equal to your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)

Anax, Hardened in the Forge

Anax's power is equal to your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)
Whenever Anax or another nontoken creature you control dies, create a 1/1 red Satyr creature token with "This token can't block." If the creature had power 4 or greater, create two of those tokens instead.

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.)

Cathartic Reunion

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

Descent into Avernus

At the beginning of your upkeep, put two descent counters on this enchantment. Then each player creates X Treasure tokens and this enchantment deals X damage to each player, where X is the number of descent counters on this enchantment.

Squee, the Immortal

You may cast this card from your graveyard or from exile.

Anger

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

Gamble

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

Seething Song

Blazing Firesinger

This creature enters prepared. (While it's prepared, you may cast a copy of its spell. Doing so unprepares it.)

Blazing Firesinger // Seething Song

Enduring Courage

Whenever another creature you control enters, it gets +2/+0 and gains haste until end of turn.
When Enduring Courage dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Ifrit, Warden of Inferno

(As this Saga enters and after your draw step, add a lore counter.)
I — Lunge — Ifrit fights up to one other target creature.
II, III — Brimstone — Add {R}{R}{R}{R}. If Ifrit has three or more lore counters on it, exile it, then return it to the battlefield (front face up).

Clive, Ifrit's Dominant

When Clive enters, you may discard your hand, then draw cards equal to your devotion to red. (Each {R} in the mana costs of permanents you control counts toward your devotion to red.)
{4}{R}{R}, {T}: Exile Clive, then return it to the battlefield transformed under its owner's control. Activate only as a sorcery.

Clive, Ifrit's Dominant // Ifrit, Warden of Inferno

Brash Taunter

Indestructible
Whenever this creature is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: This creature fights another target creature.

Summon: G.F. Ifrit

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I, II — You may discard a card. If you do, draw a card.
III, IV — Add {R}.

Pyroblast

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

Atsushi, the Blazing Sky

Flying, trample
When Atsushi dies, choose one —
• Exile the top two cards of your library. Until the end of your next turn, you may play those cards.
• Create three Treasure tokens.

Maybe

Terror of the Peaks

Flying
Spells your opponents cast that target this creature cost an additional 3 life to cast.
Whenever another creature you control enters, this creature deals damage equal to that creature's power to any target.

Sunset Strikemaster

{T}: Add {R}.
{2}{R}, {T}, Sacrifice this creature: It deals 6 damage to target creature with flying.

Untimely Malfunction

Choose one —
• Destroy target artifact.
• Change the target of target spell or ability with a single target.
• One or two target creatures can't block this turn.

Count on Luck

At the beginning of your upkeep, exile the top card of your library. You may play that card this turn.

Leyline Tyrant

Flying
You don't lose unspent red mana as steps and phases end.
When this creature dies, you may pay any amount of {R}. When you do, it deals that much damage to any target.

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Charging Strifeknight

Combustible Gearhulk

First strike
When this creature enters, target opponent may have you draw three cards. If the player doesn't, you mill three cards, then this creature deals damage to that player equal to the total mana value of those cards.

Goldspan Dragon

Flying, haste
Whenever this creature attacks or becomes the target of a spell, create a Treasure token.
Treasures you control have "{T}, Sacrifice this artifact: Add two mana of any one color."

Tecutlan, the Searing Rift

(Transforms from Brass's Tunnel-Grinder.)
{T}: Add {R}.
Whenever you cast a permanent spell using mana produced by Tecutlan, discover X, where X is that spell's mana value.

Brass's Tunnel-Grinder

When Brass's Tunnel-Grinder enters, discard any number of cards, then draw that many cards plus one.
At the beginning of your end step, if you descended this turn, put a bore counter on Brass's Tunnel-Grinder. Then if there are three or more bore counters on it, remove those counters and transform it. (You descended if a permanent card was put into your graveyard from anywhere.)

Brass's Tunnel-Grinder // Tecutlan, the Searing Rift

Ogre Battledriver

Whenever another creature you control enters, that creature gets +2/+0 and gains haste until end of turn. (It can attack and {T} this turn.)

Chandra's Ignition

Target creature you control deals damage equal to its power to each other creature and each opponent.

Tersa Lightshatter

Haste
When Tersa Lightshatter enters, discard up to two cards, then draw that many cards.
Whenever Tersa Lightshatter attacks, if there are seven or more cards in your graveyard, exile a card at random from your graveyard. You may play that card this turn.

Professional Face-Breaker

Menace
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token.
Sacrifice a Treasure: Exile the top card of your library. You may play that card this turn.

Blasphemous Act

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

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Nyx Lotus

Nyx Lotus enters tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Gogo, Mysterious Mime

At the beginning of combat on your turn, you may have Gogo become a copy of another target creature you control until end of turn, except its name is Gogo, Mysterious Mime. If you do, Gogo and that creature each get +2/+0 and gain haste until end of turn and attack this turn if able.

Cursed Mirror

{T}: Add {R}.
As this artifact enters, you may have it become a copy of any creature on the battlefield until end of turn, except it has haste.

The Core

(Transforms from Matzalantli.)
Fathomless descent — {T}: Add X mana of any one color, where X is the number of permanent cards in your graveyard.

Matzalantli, the Great Door

{T}: Draw a card, then discard a card.
{4}, {T}: Transform Matzalantli. Activate only if there are four or more permanent types among cards in your graveyard. (Artifact, battle, creature, enchantment, land, and planeswalker are permanent types.)