Return target nonland permanent you don't control to its owner's hand. Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Shadow (This creature can block or be blocked by only creatures with shadow.) If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it. {T}, Sacrifice Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Menace Whenever you sacrifice a creature, you may pay {U/B}. If you do, draw a card. ({U/B} can be paid with either {U} or {B}.) {1}, Sacrifice a creature: Kels, Fight Fixer gains indestructible until end of turn.

Flying Whenever a player casts their second spell each turn, Ledger Shredder connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.) Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Equipped creature gets +1/-1. Whenever equipped creature dies, draw two cards. Equip {1}

As Species Specialist enters the battlefield, choose a creature type. Whenever a creature of the chosen type dies, you may draw a card.

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

({U/P} can be paid with either {U} or 2 life.) Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

{1}, {T}: Acorn Catapult deals 1 damage to any target. That permanent's controller or that player creates a 1/1 green Squirrel creature token.

Trample, haste When Clackbridge Troll enters the battlefield, target opponent creates three 0/1 white Goat creature tokens. At the beginning of combat on your turn, any opponent may sacrifice a creature. If a player does, tap Clackbridge Troll, you gain 3 life, and you draw a card.

Whenever a nontoken creature enters the battlefield, if Genesis Chamber is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Hunted Phantasm can't be blocked. When Hunted Phantasm enters the battlefield, target opponent creates five 1/1 red Goblin creature tokens.

At the beginning of each player's upkeep, that player mills a card. Then they create X 1/1 black Minion creature tokens, where X is the milled card's mana value.

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

{2}, {T}: Add {B} for each Swamp you control.

Whenever City of Brass becomes tapped, it deals 1 damage to you. {T}: Add one mana of any color.

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

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

{T}: Add one mana of any color. Whenever you tap Forbidden Orchard for mana, target opponent creates a 1/1 colorless Spirit creature token.

({T}: Add {U}.)

{T}, Pay 1 life: Add one mana of any color.

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Morphic Pool enters the battlefield tapped unless you have two or more opponents. {T}: Add {U} or {B}.

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

({T}: Add {B}.)

{T}: Add {C}. {T}: Add {U} or {B}. Underground River deals 1 damage to you.

({T}: Add {U} or {B}.)

Each land is a Swamp in addition to its other land types.

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Until your next turn, creatures target player controls have base power and toughness 1/1. Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Until end of turn, each creature target player controls loses all abilities and becomes a blue Frog with base power and toughness 1/1.

Whenever Sludge Monster enters the battlefield or attacks, put a slime counter on up to one other target creature. Non-Horror creatures with slime counters on them lose all abilities and have base power and toughness 2/2.

Indestructible Equipped creature has indestructible. Equip {2}

Enchant creature Enchanted creature has deathtouch and indestructible. Morph—Sacrifice another creature. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) As Gift of Doom is turned face up, you may attach it to a creature.

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

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

Whenever a creature dies, put a charge counter on Black Market. At the beginning of your precombat main phase, add {B} for each charge counter on Black Market.

Imprint — When Chrome Mox enters the battlefield, you may exile a nonartifact, nonland card from your hand. {T}: Add one mana of any of the exiled card's colors.

Add {B}{B}{B}.

{1}, {T}: Add {U}{B}.

Grim Monolith doesn't untap during your untap step. {T}: Add {C}{C}{C}. {4}: Untap Grim Monolith.

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you. {T}: Add {C}{C}.

Mana Vault doesn't untap during your untap step. At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault. At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you. {T}: Add {C}{C}{C}.

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

If Mox Diamond would enter the battlefield, you may discard a land card instead. If you do, put Mox Diamond onto the battlefield. If you don't, put it into its owner's graveyard. {T}: Add one mana of any color.

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.

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

Sacrifice a creature: Add {C}{C}.

Sacrifice a creature: Add one mana of any color.

Search your library for a card, put that card into your hand, then shuffle.

Whenever Ayara, First of Locthwain or another black creature enters the battlefield under your control, each opponent loses 1 life and you gain 1 life. {T}, Sacrifice another black creature: Draw a card.

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Enchant creature Enchanted creature has lifelink and "Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature." (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Whenever a creature you don't control dies, return it to the battlefield under your control with an additional +1/+1 counter on it at the beginning of the next end step. That creature is a black Zombie in addition to its other colors and types.

When Massacre Wurm enters the battlefield, creatures your opponents control get -2/-2 until end of turn. Whenever a creature an opponent controls dies, that player loses 2 life.

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

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.

Counter target spell.

If you control a commander, you may cast this spell without paying its mana cost. Counter target noncreature spell.

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost. Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost. Counter target spell.

Flying When Gilded Drake enters the battlefield, exchange control of Gilded Drake and up to one target creature an opponent controls. If you don't or can't make an exchange, sacrifice Gilded Drake. This ability still resolves if its target becomes illegal.

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Counter target noncreature spell.

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.)

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.