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}

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.

Vega, the Watcher

Flying
Whenever you cast a spell from anywhere other than your hand, draw a card.

Gitaxian Probe

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

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Command Beacon

{T}: Add {C}.
{T}, Sacrifice Command Beacon: Put your commander into your hand from the command zone.

Loran's Escape

Target artifact or creature gains hexproof and indestructible until end of turn. Scry 1.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Mother of Runes

{T}: Target creature you control gains protection from the color of your choice until end of turn.

Fellwar Stone

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

Reliquary Tower

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

Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Mystic Gate

{T}: Add {C}.
{W/U}, {T}: Add {W}{W}, {W}{U}, or {U}{U}.

Baral, Chief of Compliance

Instant and sorcery spells you cast cost {1} less to cast.
Whenever a spell or ability you control counters a spell, you may draw a card. If you do, discard a card.

Reconnaissance

{0}: Remove target attacking creature you control from combat and untap it. (If you activate during end of combat, the creature will untap after it deals combat damage.)

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

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.

Thirst for Discovery

Draw three cards. Then discard two cards unless you discard a basic land card.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Single Combat

Each player chooses a creature or planeswalker they control, then sacrifices the rest. Players can't cast creature or planeswalker spells until the end of your next turn.

Thought Vessel

Mystical Tutor

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

Sanctum of Eternity

{T}: Add {C}.
{2}, {T}: Return target commander you own from the battlefield to your hand. Activate only during your turn.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Spellseeker

When Spellseeker enters, you may search your library for an instant or sorcery card with mana value 2 or less, reveal it, put it into your hand, then shuffle.

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Zethi, Arcane Blademaster

Multikicker {W/U}
When Zethi, Arcane Blademaster enters, exile up to X target instant cards from your graveyard, where X is the number of times Zethi was kicked. Put a kick counter on each of them.
Whenever Zethi attacks, copy each exiled card you own with a kick counter on it. You may cast the copies.

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

Crystal Shard

{3}, {T} or {U}, {T}: Return target creature to its owner's hand unless its controller pays {1}.

Unsummon

Return target creature to its owner's hand.

Vesuvan Duplimancy

Whenever you cast a spell that targets only a single artifact or creature you control, create a token that's a copy of that artifact or creature, except it's not legendary.

Geralf, the Fleshwright

Whenever you cast a spell during your turn other than your first spell that turn, create a 2/2 blue and black Zombie Rogue creature token.
Whenever a Zombie you control enters, put a +1/+1 counter on it for each other Zombie that entered the battlefield under your control this turn.

Access Tunnel

{T}: Add {C}.
{3}, {T}: Target creature with power 3 or less can't be blocked this turn.

Sol Ring

Thought Scour

Target player mills two cards.
Draw a card.

Curate

Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Draw a card.

Thirst for Knowledge

Draw three cards. Then discard two cards unless you discard an artifact card.

Shelter

Target creature you control gains protection from the color of your choice until end of turn.
Draw a card.

Island

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Command Tower

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

Final Iteration

Flying
Wizards you control get +2/+1 and have flying.
Whenever you cast an instant or sorcery spell, create a 1/1 blue Human Wizard creature token.

Docent of Perfection

Flying
Whenever you cast an instant or sorcery spell, create a 1/1 blue Human Wizard creature token. Then if you control three or more Wizards, transform Docent of Perfection.

Docent of Perfection // Final Iteration

Thunderclap Drake

Flying
Instant and sorcery spells you cast cost {1} less to cast.
{2}{U}, Sacrifice Thunderclap Drake: When you next cast an instant or sorcery spell this turn, copy it for each time you've cast your commander from the command zone this game. You may choose new targets for the copies.

Boon of Safety

Put a shield counter on target creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Scry 1.

Talisman of Progress

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

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Sage of the Beyond

Flying
Spells you cast from anywhere other than your hand cost {2} less to cast.
Foretell {4}{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.)

Hallowed Fountain

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

Archmage Emeritus

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

Careful Study

Snap

Return target creature to its owner's hand. Untap up to two lands.

Faithful Mending

You gain 2 life, draw two cards, then discard two cards.
Flashback {1}{W}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Primal Wellspring

(Transforms from Primal Amulet.)
{T}: Add one mana of any color. When that mana is spent to cast an instant or sorcery spell, copy that spell and you may choose new targets for the copy.

Primal Amulet

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, put a charge counter on Primal Amulet. Then if there are four or more charge counters on it, you may remove those counters and transform it.

Primal Amulet // Primal Wellspring

Time Wipe

Return a creature you control to its owner's hand, then destroy all creatures.

Arcane Signet

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Tragic Arrogance

For each player, you choose from among the permanents that player controls an artifact, a creature, an enchantment, and a planeswalker. Then each player sacrifices all other nonland permanents they control.

Sky Diamond

Leap

Target creature gains flying until end of turn.
Draw a card.

Slash the Ranks

Destroy all creatures and planeswalkers except for commanders.

Counterspell

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Marble Diamond

Marble Diamond enters tapped.
{T}: Add {W}.

Consider

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

Time Warp

Target player takes an extra turn after this one.

Azorius Signet

Approach of the Second Sun

If this spell was cast from your hand and you've cast another spell named Approach of the Second Sun this game, you win the game. Otherwise, put Approach of the Second Sun into its owner's library seventh from the top and you gain 7 life.

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Valorous Stance

Choose one —
• Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)
• Destroy target creature with toughness 4 or greater.

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Plains

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Frantic Search

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

Mind Stone

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

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.