Copy Artifact

You may have Copy Artifact enter as a copy of any artifact on the battlefield, except it's an enchantment in addition to its other types.

Evil Twin

You may have Evil Twin enter as a copy of any creature on the battlefield, except it has "{U}{B}, {T}: Destroy target creature with the same name as this creature."

Archaeomender

When Archaeomender enters, return target artifact card from your graveyard to your hand.

Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Ancient Silver Dragon

Flying
Whenever Ancient Silver Dragon deals combat damage to a player, roll a d20. Draw cards equal to the result. You have no maximum hand size for the rest of the game.

Brainstealer Dragon

Flying
At the beginning of your end step, exile the top card of each opponent's library. You may play those cards for as long as they remain exiled. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.
Whenever a nonland permanent an opponent owns enters the battlefield under your control, they lose life equal to its mana value.

Crystalline Resonance

Whenever you cycle a card, you may have Crystalline Resonance become a copy of another target permanent until your next turn, except it has this ability.

Ancient Brass Dragon

Flying
Whenever Ancient Brass Dragon deals combat damage to a player, roll a d20. When you do, put any number of target creature cards with total mana value X or less from graveyards onto the battlefield under your control, where X is the result.

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters, choose a creature type.
Whenever another creature you control of the chosen type enters, put a +1/+1 counter on Bloodline Pretender.

Curse of Echoes

Enchant player
Whenever enchanted player casts an instant or sorcery spell, each other player may copy that spell and may choose new targets for the copy they control.

Clone Legion

For each creature target player controls, create a token that's a copy of that creature.

Body Double

You may have Body Double enter as a copy of any creature card in a graveyard.

Archetype of Imagination

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

Artificer Class

(Gain the next level as a sorcery to add its ability.)
The first artifact spell you cast each turn costs {1} less to cast.
{1}{U}: Level 2
When this Class becomes level 2, reveal cards from the top of your library until you reveal an artifact card. Put that card into your hand and the rest on the bottom of your library in a random order.
{5}{U}: Level 3
At the beginning of your end step, create a token that's a copy of target artifact you control.

Ancient Gold Dragon

Flying
Whenever Ancient Gold Dragon deals combat damage to a player, roll a d20. You create a number of 1/1 blue Faerie Dragon creature tokens with flying equal to the result.

Cryptoplasm

At the beginning of your upkeep, you may have Cryptoplasm become a copy of another target creature, except it has this ability.

Aboleth Spawn

Flash
Ward {2}
Probing Telepathy — Whenever a creature entering under an opponent's control causes a triggered ability of that creature to trigger, you may copy that ability. You may choose new targets for the copy.

Dragonlord Silumgar

Flying, deathtouch
When Dragonlord Silumgar enters, gain control of target creature or planeswalker for as long as you control Dragonlord Silumgar.

Activated Sleeper

Flash
You may have Activated Sleeper enter as a copy of any creature card in a graveyard that was put there from the battlefield this turn, except it's a Phyrexian in addition to its other types.

Acid-Spewer Dragon

Flying, deathtouch
Megamorph {5}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When Acid-Spewer Dragon is turned face up, put a +1/+1 counter on each other Dragon creature you control.

Deekah, Fractal Theorist

Magecraft — Whenever you cast or copy an instant or sorcery spell, create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is that spell's mana value.
{3}{U}: Target creature token can't be blocked this turn.

Ao, the Dawn Sky

Flying, vigilance
When Ao, the Dawn Sky dies, choose one —
• Look at the top seven cards of your library. Put any number of nonland permanent cards with total mana value 4 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.
• Put two +1/+1 counters on each permanent you control that's a creature or Vehicle.

Callidus Assassin

Flash
Polymorphine — You may have Callidus Assassin enter tapped as a copy of any creature on the battlefield, except it has "When this creature enters, destroy up to one other target creature with the same name as this creature."

Aphetto Runecaster

Whenever a permanent is turned face up, you may draw a card.

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Ravos, Soultender

Flying
Other creatures you control get +1/+1.
At the beginning of your upkeep, you may return target creature card from your graveyard to your hand.
Partner (You can have two commanders if both have partner.)

Copy Enchantment

You may have Copy Enchantment enter as a copy of any enchantment on the battlefield.

Dimir Doppelganger

{1}{U}{B}: Exile target creature card from a graveyard. Dimir Doppelganger becomes a copy of that card, except it has this ability.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Ancestor Dragon

Flying
Whenever one or more creatures you control attack, you gain 1 life for each attacking creature.

Clever Impersonator

You may have Clever Impersonator enter as a copy of any nonland permanent on the battlefield.

Arcane Investigator

Search the Room — {5}{U}: Roll a d20.
1—9 | Draw a card.
10—20 | Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Iymrith, Desert Doom

Flying
Iymrith, Desert Doom has ward {4} as long as it's untapped.
Whenever Iymrith deals combat damage to a player, draw a card. Then if you have fewer than three cards in hand, draw cards equal to the difference.

Astral Dragon

Flying
Project Image — When Astral Dragon enters, create two tokens that are copies of target noncreature permanent, except they're 3/3 Dragon creatures in addition to their other types, and they have flying.

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis to its owner's hand.

Cackling Counterpart

Create a token that's a copy of target creature you control.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Apprentice Wizard

Academy Loremaster

At the beginning of each player's draw step, that player may draw an additional card. If they do, spells they cast this turn cost {2} more to cast.