Sol Ring

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Eris, Roar of the Storm

This spell costs {2} less to cast for each different mana value among instant and sorcery cards in your graveyard.
Flying, prowess
Whenever you cast your second spell each turn, create a 4/4 red Dragon Elemental creature token with flying and prowess.

Stubborn Denial

Counter target noncreature spell unless its controller pays {1}.
Ferocious — If you control a creature with power 4 or greater, counter that spell instead.

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Izzet Signet

Imposing Grandeur

Each player may discard their hand and draw cards equal to the greatest mana value of a commander they own on the battlefield or in the command zone.

Soldier

Isengard Unleashed

Damage can't be prevented this turn. If a source you control would deal damage this turn to an opponent or a permanent an opponent controls, it deals triple that damage instead.
Flashback {4}{R}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Surge to Victory

Exile target instant or sorcery card from your graveyard. Creatures you control get +X/+0 until end of turn, where X is that card's mana value. Whenever a creature you control deals combat damage to a player this turn, copy the exiled card. You may cast the copy without paying its mana cost.

Otherworldly Gaze

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Guttersnipe

Whenever you cast an instant or sorcery spell, Guttersnipe deals 2 damage to each opponent.

First Mate Ragavan

Elemental Masterpiece

Create two 4/4 blue and red Elemental creature tokens.
{U/R}{U/R}, Discard Elemental Masterpiece: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Mountain

Strategic Planning

Look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.

Elemental Eruption

Create a 4/4 red Dragon Elemental creature token with flying and prowess.
Storm (When you cast this spell, copy it for each spell cast before it this turn.)

The Great Work

(As this Saga enters and after your draw step, add a lore counter.)
I — The Great Work deals 3 damage to target opponent and each creature they control.
II — Create three Treasure tokens.
III — Until end of turn, you may cast instant and sorcery spells from any graveyard. If a spell cast this way would be put into a graveyard, exile it instead. Exile The Great Work, then return it to the battlefield (front face up).

Urabrask

First strike
Whenever you cast an instant or sorcery spell, Urabrask deals 1 damage to target opponent. Add {R}.
{R}: Exile Urabrask, then return it to the battlefield transformed under its owner's control. Activate only as a sorcery and only if you've cast three or more instant and/or sorcery spells this turn.

Urabrask // The Great Work

Bird

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Cathartic Reunion

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

Counterspell

Thundering Falls

({T}: Add {U} or {R}.)
Thundering Falls enters tapped.
When Thundering Falls enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Visions of Duplicity

Exchange control of two target creatures you don't control.
Flashback {8}{U}{U}. This spell costs {X} less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Copy

(This token can be used to represent a token that's a copy of a permanent.)

Alhammarret's Archive

If you would gain life, you gain twice that much life instead.
If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Fiery Emancipation

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

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.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

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.)

Quiet Speculation

Search target player's library for up to three cards with flashback and put them into that player's graveyard. Then the player shuffles.

Visions of Ruin

Each opponent sacrifices an artifact. For each artifact sacrificed this way, you create a Treasure token.
Flashback {8}{R}{R}. This spell costs {X} less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Balmor, Battlemage Captain

Flying
Whenever you cast an instant or sorcery spell, creatures you control get +1/+0 and gain trample until end of turn.

Wizards of Thay

Myriad (Whenever this creature 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.)
Instant and sorcery spells you cast cost {1} less to cast.
You may cast sorcery spells as though they had flash.

Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Steam Vents

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

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.

Thought Scour

Target player mills two cards.
Draw a card.

Lórien Revealed

Draw three cards.
Islandcycling {1} ({1}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Blasphemous Act

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

Case of the Ransacked Lab

Instant and sorcery spells you cast cost {1} less to cast.
To solve — You've cast four or more instant and sorcery spells this turn. (If unsolved, solve at the beginning of your end step.)
Solved — Whenever you cast an instant or sorcery spell, draw a card.

Personal Tutor

Search your library for a sorcery card, reveal it, then shuffle and put that card on top.

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Jori En, Ruin Diver

Whenever you cast your second spell each turn, draw a card.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Frostboil Snarl

As Frostboil Snarl enters, you may reveal an Island or Mountain card from your hand. If you don't, Frostboil Snarl enters tapped.
{T}: Add {U} or {R}.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Creative Outburst

Creative Outburst deals 5 damage to any target. Look at the top five cards of your library. Put one of them into your hand and the rest on the bottom of your library in a random order.
{U/R}{U/R}, Discard Creative Outburst: Create a Treasure token.

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Elemental

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Veyran, Voice of Duality

Magecraft — Whenever you cast or copy an instant or sorcery spell, Veyran, Voice of Duality gets +1/+1 until end of turn.
If you casting or copying an instant or sorcery spell causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Ashling, Flame Dancer

You don't lose unspent red mana as steps and phases end.
Magecraft — Whenever you cast or copy an instant or sorcery spell, discard a card, then draw a card. If this is the second time this ability has resolved this turn, Ashling, Flame Dancer deals 2 damage to each opponent and each creature they control. If it's the third time, add {R}{R}{R}{R}.

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 artifact: Add one mana of any color.")

Unwind

Counter target noncreature spell. Untap up to three lands.

Contingency Plan

Surveil 5. (Look at the top five cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Rush of Knowledge

Draw cards equal to the highest mana value among permanents you control.

Intuition

Search your library for three cards and reveal them. Target opponent chooses one. Put that card into your hand and the rest into your graveyard. Then shuffle.

Island

Rewind

Counter target spell. Untap up to four lands.

Arcane Signet

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

Firebrand Archer

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

Baral and Kari Zev

First strike, menace
Whenever you cast your first instant or sorcery spell each turn, you may cast a spell with lesser mana value that shares a card type with it from your hand without paying its mana cost. If you don't, create First Mate Ragavan, a legendary 2/1 red Monkey Pirate creature token. It gains haste until end of turn.

Mental Note

Dragon Elemental

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Gut Shot

({R/P} can be paid with either {R} or 2 life.)
Gut Shot deals 1 damage to any target.

Echo of Eons

Each player shuffles their hand and graveyard into their library, then draws seven cards.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Demand Answers

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

Magma Opus

Magma Opus deals 4 damage divided as you choose among any number of targets. Tap two target permanents. Create a 4/4 blue and red Elemental creature token. Draw two cards.
{U/R}{U/R}, Discard Magma Opus: Create a Treasure token.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Big Score

Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Furious

Furious deals 3 damage to each creature without flying.

Fast

Fast // Furious

Command Tower

Boon of the Wish-Giver

Draw four cards.
Cycling {1} ({1}, Discard this card: Draw a card.)

Fiery Inscription

When Fiery Inscription enters, the Ring tempts you.
Whenever you cast an instant or sorcery spell, Fiery Inscription deals 2 damage to each opponent.