Splitting the Powerstone

As an additional cost to cast this spell, sacrifice an artifact.
Create two tapped Powerstone tokens. If the sacrificed artifact was legendary, draw a card. (The tokens are artifacts with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Bhaal's Invoker

Scorching Ray — {8}: Bhaal's Invoker deals 4 damage to each opponent.

Chaos Wand

{4}, {T}: Target opponent exiles cards from the top of their library until they exile an instant or sorcery card. You may cast that card without paying its mana cost. Then put the exiled cards that weren't cast this way on the bottom of that library in a random order.

League Guildmage

{3}{U}, {T}: Draw a card.
{X}{R}, {T}: Copy target instant or sorcery spell you control with mana value X. You may choose new targets for the copy.

Champion of Wits

When Champion of Wits enters the battlefield, you may draw cards equal to its power. If you do, discard two cards.
Eternalize {5}{U}{U} ({5}{U}{U}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Snake Wizard with no mana cost. Eternalize only as a sorcery.)

Flamewave Invoker

{7}{R}: Flamewave Invoker deals 5 damage to target player or planeswalker.

Stern Lesson

Draw two cards, then discard a card. Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Hall of Tagsin

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}, {T}: Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

The Reality Chip

You may look at the top card of your library any time.
As long as The Reality Chip is attached to a creature, you may play lands and cast spells from the top of your library.
Reconfigure {2}{U} ({2}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Battlemage's Bracers

Equipped creature has haste.
Whenever an ability of equipped creature is activated, if it isn't a mana ability, you may pay {1}. If you do, copy that ability. You may choose new targets for the copy.
Equip {2}

Queen Kayla bin-Kroog

{4}, {T}: Discard all the cards in your hand, then draw that many cards. You may choose an artifact or creature card with mana value 1 you discarded this way, then do the same for artifact or creature cards with mana values 2 and 3. Return those cards to the battlefield. Activate only as a sorcery.

Eidolon of Philosophy

{6}{U}, Sacrifice Eidolon of Philosophy: Draw three cards.

Triskaidekaphile

You have no maximum hand size.
At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game.
{3}{U}: Draw a card.

Rings of Brighthearth

Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.

Patriar's Seal

{T}: Add one mana of any color.
{1}, {T}: Untap target legendary creature you control.

Gold Myr

Bane's Invoker

Wind Walk — {8}: Up to two target creatures each get +2/+2 and gain flying until end of turn.

Vizier of Many Faces

You may have Vizier of Many Faces enter the battlefield as a copy of any creature on the battlefield, except if Vizier of Many Faces was embalmed, the token has no mana cost, it's white, and it's a Zombie in addition to its other types.
Embalm {3}{U}{U}

Visions of Phyrexia

At the beginning of your upkeep, exile the top card of your library. You may play that card this turn.
At the beginning of your end step, if you didn't play a card from exile this turn, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Vhal, Candlekeep Researcher

Vigilance
{T}: Add an amount of {C} equal to Vhal, Candlekeep Researcher's toughness. This mana can't be spent to cast spells from your hand.
Choose a Background (You can have a Background as a second commander.)

Dawnglare Invoker

Flying
{8}: Tap all creatures target player controls.

Shark Typhoon

Whenever you cast a noncreature spell, create an X/X blue Shark creature token with flying, where X is that spell's mana value.
Cycling {X}{1}{U} ({X}{1}{U}, Discard this card: Draw a card.)
When you cycle Shark Typhoon, create an X/X blue Shark creature token with flying.

Heliod, God of the Sun

Indestructible
As long as your devotion to white is less than five, Heliod isn't a creature. (Each {W} in the mana costs of permanents you control counts toward your devotion to white.)
Other creatures you control have vigilance.
{2}{W}{W}: Create a 2/1 white Cleric enchantment creature token.

Excavation Explosion

Excavation Explosion deals 3 damage to any target. Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Witching Well

When Witching Well enters the battlefield, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)
{3}{U}, Sacrifice Witching Well: Draw two cards.

Worn Powerstone

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

Mindslaver

{4}, {T}, Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for the player.)

Deem Worthy

Deem Worthy deals 7 damage to target creature.
Cycling {3}{R} ({3}{R}, Discard this card: Draw a card.)
When you cycle Deem Worthy, you may have it deal 2 damage to target creature.

Treasure Chest

{4}, Sacrifice Treasure Chest: Roll a d20.
1 | Trapped! — You lose 3 life.
2—9 | Create five Treasure tokens.
10—19 | You gain 3 life and draw three cards.
20 | Search your library for a card. If it's an artifact card, you may put it onto the battlefield. Otherwise, put that card into your hand. Then shuffle.

Halo Fountain

{W}, {T}, Untap a tapped creature you control: Create a 1/1 green and white Citizen creature token.
{W}{W}, {T}, Untap two tapped creatures you control: Draw a card.
{W}{W}{W}{W}{W}, {T}, Untap fifteen tapped creatures you control: You win the game.

Blighted Cataract

{T}: Add {C}.
{5}{U}, {T}, Sacrifice Blighted Cataract: Draw two cards.

The Peregrine Dynamo

Haste
{1}, {T}: Copy target activated or triggered ability you control from another legendary source that's not a commander. You may choose new targets for the copy. (Mana abilities can't be targeted.)

Memnarch

{1}{U}{U}: Target permanent becomes an artifact in addition to its other types. (This effect lasts indefinitely.)
{3}{U}: Gain control of target artifact. (This effect lasts indefinitely.)

Nimbleclaw Adept

Bigby's Hand — {T}: Untap two other target permanents. Activate only as a sorcery and only once each turn.

Adorned Pouncer

Double strike
Eternalize {3}{W}{W} ({3}{W}{W}, Exile this card from your graveyard: Create a token that's a copy of it, except it's a 4/4 black Zombie Cat with no mana cost. Eternalize only as a sorcery.)

Geology Enthusiast

At the beginning of your end step, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")
{6}: Draw a card and put a +1/+1 counter on Geology Enthusiast.

Gilded Lotus

Ornithopter of Paradise

Captivating Crew

{3}{R}: Gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn. Activate only as a sorcery.

Tymora's Invoker

Illusionist's Bracers

Whenever an ability of equipped creature is activated, if it isn't a mana ability, copy that ability. You may choose new targets for the copy.
Equip {3}

Thran Dynamo

Bronze Walrus

When Bronze Walrus enters the battlefield, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)
{T}: Add one mana of any color.

Keening Stone

{5}, {T}: Target player mills X cards, where X is the number of cards in that player's graveyard.

Phyrexian Processor

As Phyrexian Processor enters the battlefield, pay any amount of life.
{4}, {T}: Create an X/X black Phyrexian Minion creature token, where X is the life paid as Phyrexian Processor entered the battlefield.

Brittle Effigy

{4}, {T}, Exile Brittle Effigy: Exile target creature.

Faerie Formation

Flying
{3}{U}: Create a 1/1 blue Faerie creature token with flying. Draw a card.

Mystic Archaeologist

Dynaheir, Invoker Adept

Haste
You may activate abilities of other creatures you control as though those creatures had haste.
{T}: When you next activate an ability that isn't a mana ability this turn by spending four or more mana to activate it, copy that ability. You may choose new targets for the copy.

Lavafume Invoker

{8}: Creatures you control get +3/+0 until end of turn.

Drumbellower

Flying
Untap all creatures you control during each other player's untap step.

Iron Myr

Orochi Hatchery

Orochi Hatchery enters the battlefield with X charge counters on it.
{5}, {T}: Create a 1/1 green Snake creature token for each charge counter on Orochi Hatchery.

Palladium Myr

Memorial to Genius

Memorial to Genius enters the battlefield tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice Memorial to Genius: Draw two cards.

Silver Myr

Lithoform Engine

{2}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy.
{3}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.
{4}, {T}: Copy target permanent spell you control. (The copy becomes a token.)

Planar Bridge

{8}, {T}: Search your library for a permanent card, put it onto the battlefield, then shuffle.

Sol Ring

Karn, Living Legacy

+1: Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")
−1: Pay any amount of mana. Look at that many cards from the top of your library, then put one of those cards into your hand and the rest on the bottom of your library in a random order.
−7: You get an emblem with "Tap an untapped artifact you control: This emblem deals 1 damage to any target."

Impulsive Pilferer

When Impulsive Pilferer dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Encore {3}{R} ({3}{R}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)