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.")

Cursed Mirror

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

The Fifteenth Doctor

Whenever The Fifteenth Doctor enters or attacks, mill three cards. You may put an artifact card with mana value 2 or 3 from among them into your hand.
The first nonartifact spell you cast each turn has improvise. (Your artifacts can help cast that spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Ovika, Enigma Goliath

Flying
Ward—{3}, Pay 3 life.
Whenever you cast a noncreature spell, create X 1/1 red Phyrexian Goblin creature tokens, where X is the mana value of that spell. They gain haste until end of turn.

Enthusiastic Mechanaut

Flying
Artifact spells you cast cost {1} less to cast.

Izzet Signet

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Sonic Screwdriver

{T}: Add one mana of any color.
{1}, {T}: Untap another target artifact.
{2}, {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{3}, {T}: Target creature can't be blocked this turn.

Winged Boots

Equipped creature has flying and ward {4}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
Equip {1}

Talisman of Conviction

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

Emry, Lurker of the Loch

This spell costs {1} less to cast for each artifact you control.
When Emry, Lurker of the Loch enters, mill four cards.
{T}: Choose target artifact card in your graveyard. You may cast that card this turn. (You still pay its costs. Timing rules still apply.)

Whirlwind of Thought

Whenever you cast a noncreature spell, draw a card.

Birthright Boon

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Kellan, the Fae-Blooded

Double strike
Other creatures you control get +1/+0 for each Aura and Equipment attached to Kellan, the Fae-Blooded.

Kellan, the Fae-Blooded // Birthright Boon

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.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Reckoner Bankbuster

Reckoner Bankbuster enters with three charge counters on it.
{2}, {T}, Remove a charge counter from Reckoner Bankbuster: Draw a card. Then if there are no charge counters on Reckoner Bankbuster, create a Treasure token and a 1/1 colorless Pilot creature token with "This creature crews Vehicles as though its power were 2 greater."
Crew 3

White Sun's Twilight

You gain X life. Create X 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This creature can't block." If X is 5 or more, destroy all other creatures. (Players dealt combat damage by a creature with toxic 1 also get a poison counter.)

Robe of Stars

Equipped creature gets +0/+3.
Astral Projection — {1}{W}: Equipped creature phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)
Equip {1}

Sword of the Realms

Equipped creature gets +2/+0 and has vigilance.
Whenever equipped creature dies, return it to its owner's hand.
Equip {1}{W}

Halvar, God of Battle

Creatures you control that are enchanted or equipped have double strike.
At the beginning of each combat, you may attach target Aura or Equipment attached to a creature you control to target creature you control.

Halvar, God of Battle // Sword of the Realms

Goldspan Dragon

Flying, haste
Whenever Goldspan Dragon 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."

Peri Brown

The first historic spell you cast each turn has convoke. (Your creatures can help cast it. Each creature you tap while casting it pays for {1} or one mana of that creature's color.)
Doctor's companion (You can have two commanders if the other is the Doctor.)

Sevinne's Reclamation

Return target permanent card with mana value 3 or less from your graveyard to the battlefield. If this spell was cast from a graveyard, you may copy this spell and may choose a new target for the copy.
Flashback {4}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Boros Signet

K-9, Mark I

Negative — As long as K-9, Mark I is untapped, other legendary creatures you control have ward {1}.
Affirmative — {1}{U}, {T}: Target legendary creature can't be blocked this turn.
Doctor's companion (You can have two commanders if the other is the Doctor.)

The Eighth Doctor

When The Eighth Doctor enters, mill three cards.
Once during each of your turns, you may play a historic land or cast a historic permanent spell from your graveyard. If you do, it gains "If this permanent would leave the battlefield, exile it instead of putting it anywhere else."

Talisman of Progress

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

Big Score

Fellwar Stone

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

Shaun, Father of Synths

Whenever you attack, you may create a tapped and attacking token that's a copy of target attacking legendary creature you control other than Shaun, except it's not legendary and it's a Synth artifact creature in addition to its other types.
When Shaun leaves the battlefield, exile all Synth tokens you control.

Lightning Greaves

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

Court of Ardenvale

When Court of Ardenvale enters, you become the monarch.
At the beginning of your upkeep, return target permanent card with mana value 3 or less from your graveyard to your hand. If you're the monarch, return that permanent card to the battlefield instead.

Astor, Bearer of Blades

When Astor, Bearer of Blades enters, look at the top seven cards of your library. You may reveal an Equipment or Vehicle card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Equipment you control have equip {1}.
Vehicles you control have crew 1.

Spell Swindle

Counter target spell. Create X Treasure tokens, where X is that spell's mana value. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Talisman of Creativity

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

Lizard Blades

Double strike
Equipped creature has double strike.
Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Auton Soldier

You may have Auton Soldier enter as a copy of any creature on the battlefield, except it isn't legendary, is an artifact in addition to its other types, and 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.)

Saheeli, Sublime Artificer

Whenever you cast a noncreature spell, create a 1/1 colorless Servo artifact creature token.
−2: Target artifact you control becomes a copy of another target artifact or creature you control until end of turn, except it's an artifact in addition to its other types.

Sigarda's Aid

You may cast Aura and Equipment spells as though they had flash.
Whenever an Equipment you control enters, you may attach it to target creature you control.

Jhoira, Weatherlight Captain

Whenever you cast a historic spell, draw a card. (Artifacts, legendaries, and Sagas are historic.)

TARDIS

Flying
Whenever TARDIS attacks, if you control a Time Lord, the next spell you cast this turn has cascade and you may planeswalk.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Jeskai Ascendancy

Whenever you cast a noncreature spell, creatures you control get +1/+1 until end of turn. Untap those creatures.
Whenever you cast a noncreature spell, you may draw a card. If you do, discard a card.

Third Path Iconoclast

Whenever you cast a noncreature spell, create a 1/1 colorless Soldier artifact creature token.

Encroaching Mycosynth

Nonland permanents you control are artifacts in addition to their other types. The same is true for permanent spells you control and nonland permanent cards you own that aren't on the battlefield.

Sarah Jane Smith

Whenever you cast a historic spell, investigate. This ability triggers only once each turn. (Artifacts, legendaries, and Sagas are historic. To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Doctor's companion (You can have two commanders if the other is the Doctor.)

The Mycosynth Gardens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{X}, {T}: The Mycosynth Gardens becomes a copy of target nontoken artifact you control with mana value X.

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Azorius Signet

Bessie, the Doctor's Roadster

Haste
Whenever Bessie attacks, another target legendary creature can't be blocked this turn.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Sai, Master Thopterist

Whenever you cast an artifact spell, create a 1/1 colorless Thopter artifact creature token with flying.
{1}{U}, Sacrifice two artifacts: Draw a card.

Access Denied

Counter target spell. Create X 1/1 colorless Thopter artifact creature tokens with flying, where X is that spell's mana value.

Imposter Mech

You may have Imposter Mech enter as a copy of a creature an opponent controls, except it's a Vehicle artifact with crew 3 and it loses all other card types.
Crew 3

Goblin Engineer

When Goblin Engineer enters, you may search your library for an artifact card, put it into your graveyard, then shuffle.
{R}, {T}, Sacrifice an artifact: Return target artifact card with mana value 3 or less from your graveyard to the battlefield.

Anger

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

Dan Lewis

Noncreature, non-Equipment artifacts you control are Equipment in addition to their other types and have "Equipped creature gets +1/+0" and equip {1}.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Arcane Signet

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

Tegan Jovanka

Brave Heart — Whenever you attack, target attacking historic creature gets +1/+1 and gains indestructible until end of turn. (Artifacts, legendaries, and Sagas are historic.)
Doctor's companion (You can have two commanders if the other is the Doctor.)

Sol Ring

Optimus Prime, Autobot Leader

Living metal (During your turn, this Vehicle is also a creature.)
Trample
Whenever you attack, bolster 2. The chosen creature gains trample until end of turn. When that creature deals combat damage to a player this turn, convert Optimus Prime.

Optimus Prime, Hero

More Than Meets the Eye {2}{U}{R}{W} (You may cast this card converted for {2}{U}{R}{W}.)
At the beginning of each end step, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)
When Optimus Prime dies, return it to the battlefield converted under its owner's control.