Deranged Assistant

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Stone Idol Generator

Whenever a creature you control attacks, you get {E} (an energy counter).
{T}, Pay six {E}: Create a 6/12 colorless Construct artifact creature token with trample. Activate only as a sorcery.

Aethertide Whale

Flying
When this creature enters, you get six {E} (energy counters).
Pay {E}{E}{E}{E}: Return this creature to its owner's hand.

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.)

Wrath of God

Destroy all creatures. They can't be regenerated.

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.)

Tune the Narrative

Draw a card. You get {E}{E} (two energy counters).

Deadlock Trap

This artifact enters tapped.
When this artifact enters, you get {E}{E} (two energy counters).
{T}, Pay {E}: Tap target creature or planeswalker. Its activated abilities can't be activated this turn.

Automated Assembly Line

Whenever one or more artifact creatures you control deal combat damage to a player, you get {E} (an energy counter).
Pay {E}{E}{E}: Create a tapped 3/3 colorless Robot artifact creature token.

Space-Time Anomaly

Target player mills cards equal to your life total.

Aethersquall Ancient

Flying
At the beginning of your upkeep, you get {E}{E}{E} (three energy counters).
Pay eight {E}: Return all other creatures to their owners' hands. Activate only as a sorcery.

Cryptic Trilobite

This creature enters with X +1/+1 counters on it.
Remove a +1/+1 counter from this creature: Add {C}{C}. Spend this mana only to activate abilities.
{1}, {T}: Put a +1/+1 counter on this creature.

Aether Spike

Choose target spell. You get {E}{E} (two energy counters), then you may pay any amount of {E}. Counter that spell unless its controller pays {1} for each {E} paid this way.

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

T-45 Power Armor

When this Equipment enters, you get {E}{E} (two energy counters).
Equipped creature gets +3/+3 and doesn't untap during its controller's untap step.
At the beginning of your upkeep, you may pay {E}. If you do, untap equipped creature, then put your choice of a menace, trample, or lifelink counter on it.
Equip {3}

Cut Your Losses

Casualty 2 (As you cast this spell, you may sacrifice a creature with power 2 or greater. When you do, copy this spell and you may choose a new target for the copy.)
Target player mills half their library, rounded down.

Emry, Lurker of the Loch

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
When Emry 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.)

Brotherhood Scribe

Metalcraft — {T}: You get {E} (an energy counter). Activate only if you control three or more artifacts.
Whenever you get one or more {E} during your turn, creatures you control get +1/+1 until end of turn.

Surge Engine

Defender
{U}: This creature loses defender and gains "This creature can't be blocked."
{2}{U}: This creature becomes blue and has base power and toughness 5/4. Activate only if this creature doesn't have defender.
{4}{U}{U}: Draw three cards. Activate only if this creature is blue and only once.

Refute

Counter target spell. Draw a card, then discard a card.

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Radstorm

Storm (When you cast this spell, copy it for each spell cast before it this turn.)
Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Razorfield Ripper

Whenever this creature or equipped creature attacks, you get {E} (an energy counter), then it gets +X/+X until end of turn, where X is the amount of {E} you have.
Reconfigure—Pay {2} or {E}{E}{E}. (Pay {2} or {E}{E}{E}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Arcade Gannon

{T}: Draw a card, then discard a card. Put a quest counter on Arcade Gannon.
For Auld Lang Syne — Once during each of your turns, you may cast an artifact or Human spell from your graveyard with mana value less than or equal to the number of quest counters on Arcade Gannon.

Dovin, Hand of Control

Artifact, instant, and sorcery spells your opponents cast cost {1} more to cast.
−1: Until your next turn, prevent all damage that would be dealt to and dealt by target permanent an opponent controls.

Aetherstorm Roc

Flying
Whenever this creature or another creature you control enters, you get {E} (an energy counter).
Whenever this creature attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it and tap up to one target creature defending player controls.

Song of Stupefaction

Enchant creature or Vehicle
When this Aura enters, you may mill two cards. (You may put the top two cards of your library into your graveyard.)
Fathomless descent — Enchanted permanent gets -X/-0, where X is the number of permanent cards in your graveyard.

Rex, Cyber-Hound

Whenever Rex deals combat damage to a player, they mill two cards and you get {E}{E} (two energy counters).
Pay {E}{E}: Choose target creature card in a graveyard. Exile it with a brain counter on it. Activate only as a sorcery.
Rex has all activated abilities of all cards in exile with brain counters on them.

Aetherflux Conduit

Whenever you cast a spell, you get an amount of {E} (energy counters) equal to the amount of mana spent to cast that spell.
{T}, Pay fifty {E}: Draw seven cards. You may cast any number of spells from your hand without paying their mana costs.

Gonti's Aether Heart

Whenever Gonti's Aether Heart or another artifact you control enters, you get {E}{E} (two energy counters).
Pay eight {E}, Exile Gonti's Aether Heart: Take an extra turn after this one.

Emissary of Soulfire

When this creature enters, you get {E}{E}{E} (three energy counters).
Pay {E}{E}: Put an exalted counter on target creature you control. Activate only as a sorcery. (Whenever a creature you control attacks alone, it gets +1/+1 until end of turn for each instance of exalted among permanents you control.)

Glassblower's Puzzleknot

When this artifact enters, scry 2, then you get {E}{E}. (You get two energy counters. 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.)
{2}{U}, Sacrifice this artifact: Scry 2, then you get {E}{E}.

Deconstruction Hammer

Equipped creature gets +1/+1 and has "{3}, {T}, Sacrifice Deconstruction Hammer: Destroy target artifact or enchantment."
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Island

Sentry Bot

Flash
This spell costs {1} less to cast for each creature attacking you.
When this creature enters, you get {E} for each creature attacking you.
At the beginning of combat on your turn, you may pay {E}{E}{E}. If you do, put a +1/+1 counter on each creature you control.

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Shipwreck Moray

When this creature enters, you get {E}{E}{E}{E} (four energy counters).
Pay {E}: This creature gets +2/-2 until end of turn.

Confiscation Coup

Choose target artifact or creature. You get {E}{E}{E}{E} (four energy counters), then you may pay an amount of {E} equal to that permanent's mana value. If you do, gain control of it.

Riddle Gate Gargoyle

Flying
When this creature enters, you get {E}{E}{E} (three energy counters).
Whenever you attack, you may pay {E}{E}. When you do, target creature you control gains lifelink until end of turn.

Righteous Authority

Enchant creature
Enchanted creature gets +1/+1 for each card in its controller's hand.
At the beginning of the draw step of enchanted creature's controller, that player draws an additional card.

Aethergeode Miner

Whenever this creature attacks, you get {E}{E} (two energy counters).
Pay {E}{E}: Exile this creature, then return it to the battlefield under its owner's control.

Localized Destruction

You get {E} (an energy counter), then you may pay one or more {E}. If you do, each creature you control with power equal to the amount of {E} paid this way gains indestructible until end of turn.
Destroy all creatures.

Aetherworks Marvel

Whenever a permanent you control is put into a graveyard, you get {E} (an energy counter).
{T}, Pay six {E}: Look at the top six cards of your library. You may cast a spell from among them without paying its mana cost. Put the rest on the bottom of your library in a random order.

Fabrication Module

Whenever you get one or more {E} (energy counters), put a +1/+1 counter on target creature you control.
{4}, {T}: You get {E}.

Didn't Say Please

Counter target spell. Its controller mills three cards.

Ancestral Reminiscence

Keen Buccaneer

Vigilance
Exhaust — {1}{U}: Draw a card, then discard a card. Put a +1/+1 counter on this creature. (Activate each exhaust ability only once.)

Remorseful Cleric

Flying
Sacrifice this creature: Exile target player's graveyard.

Hope Estheim

Lifelink
At the beginning of your end step, each opponent mills X cards, where X is the amount of life you gained this turn.

Raff, Weatherlight Stalwart

Whenever you cast an instant or sorcery spell, you may tap two untapped creatures you control. If you do, draw a card.
{3}{W}{W}: Creatures you control get +1/+1 and gain vigilance until end of turn.

Marvin, Murderous Mimic

Marvin has all activated abilities of creatures you control that don't have the same name as this creature.

Thrummingbird

Flying
Whenever this creature deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Time Wipe

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

Jolted Awake

Choose up to one target artifact or creature card in your graveyard. You get {E}{E} (two energy counters). Then you may pay an amount of {E} equal to that card's mana value. If you do, return it from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Plains

Thriving Turtle

When this creature enters, you get {E}{E} (two energy counters).
Whenever this creature attacks, you may pay {E}{E}. If you do, put a +1/+1 counter on it.

Starling, Aerial Ally

Flying
When Starling enters, another target creature you control gains flying until end of turn.

Sage of Days

When this creature enters, look at the top three cards of your library. You may put one of those cards back on top of your library. Put the rest into your graveyard.

Consulate Surveillance

When this enchantment enters, you get {E}{E}{E}{E} (four energy counters).
Pay {E}{E}: Prevent all damage that would be dealt to you this turn by a source of your choice.

Lae'zel, Vlaakith's Champion

If you would put one or more counters on a creature or planeswalker you control or on yourself, put that many plus one of each of those kinds of counters on that permanent or player instead.
Choose a Background (You can have a Background as a second commander.)

Bespoke Battlewagon

{T}: You get {E}{E} (two energy counters).
{T}, Pay {E}{E}: Tap target creature.
{T}, Pay {E}{E}{E}: Draw a card.
Pay {E}{E}{E}{E}: This Vehicle becomes an artifact creature until end of turn.
Crew 4

Another Round

Exile any number of creatures you control, then return them to the battlefield under their owner's control. Then repeat this process X more times.