This spell can't be countered.

You may have Altered Ego enter the battlefield as a copy of any creature on the battlefield, except it enters with X additional +1/+1 counters on it.

Enchant creature card in a graveyard

When Animate Dead enters the battlefield, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.

Enchanted creature gets -1/-0.

{T}: Add {C}.

{1}, {T}: Until end of turn, creatures your opponents control lose hexproof and shroud and can't have hexproof or shroud.

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

{T}: Add {C}.

Basic landcycling {1} ({1}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Put target artifact or creature card from a graveyard onto the battlefield under your control. Shuffle Beacon of Unrest into its owner's library.

For each opponent, gain control of target permanent that player controls.

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

As Blood Crypt enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

Return target creature card from your graveyard to your hand. If it's a Zombie card, draw a card.

Lands you control have "{T}: Add one mana of any color."

{T}: Add one mana of any color.

({T}: Add {R} or {G}.)

Cinder Glade enters the battlefield tapped unless you control two or more basic lands.

Search your library for up to two basic land cards and/or Gate cards, put them onto the battlefield tapped, then shuffle.

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

Enchant creature

You control enchanted creature.

Enchant creature

You control enchanted creature.

Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Crumbling Necropolis enters the battlefield tapped.

{T}: Add {U}, {B}, or {R}.

You may have Dack's Duplicate enter the battlefield as a copy of any creature on the battlefield, except it has haste and dethrone. (Whenever it attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)

Indestructible

{T}: Add one mana of any color.

{T}: Exile target land card from a graveyard. Add one mana of any color.

{B}, {T}: Exile target instant or sorcery card from a graveyard. Each opponent loses 2 life.

{G}, {T}: Exile target creature card from a graveyard. You gain 2 life.

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

You may have Evil Twin enter the battlefield 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."

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

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

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

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

Enchant land

Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

Frontier Bivouac enters the battlefield tapped.

{T}: Add {G}, {U}, or {R}.

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

{X}{B}: Put target artifact or creature card with mana value X from an opponent's graveyard onto the battlefield under your control tapped. Then that player mills X cards.

You may have Glasspool Mimic enter the battlefield as a copy of a creature you control, except it's a Shapeshifter Rogue in addition to its other types.

Glasspool Shore enters the battlefield tapped.

{T}: Add {U}.

Sacrifice a creature: Draw cards equal to the sacrificed creature's power, then discard three cards.

Creatures you control have haste.

{2}{R}, {T}, Sacrifice a land: Create a 3/3 colorless Golem enchantment artifact creature token.

Draw three cards.

Choose target creature you control. Whenever that creature deals combat damage to a player or planeswalker this turn, draw that many cards.

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

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

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Khalni Territory enters the battlefield tapped.

{T}: Add {G}.

Hexproof

Whenever a creature card is put into an opponent's graveyard from anywhere, you may have Lazav, Dimir Mastermind become a copy of that card, except its name is Lazav, Dimir Mastermind, it's legendary in addition to its other types, and it has hexproof and this ability.

{T}: Add {C}.

{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Enchant creature

You control enchanted creature.

You may have Mirrormade enter the battlefield as a copy of any artifact or enchantment on the battlefield.

As an additional cost to cast this spell, sacrifice a creature.

You draw cards equal to the sacrificed creature's power, then you gain life equal to its toughness.

({T}: Add {R}.)

Create a token that's a copy of target permanent. If {R}{G} was spent to cast this spell, instead create a token that's a copy of that permanent, except the token has "When this permanent enters the battlefield, if it's a creature, it fights up to one target creature you don't control."

Whenever Nascent Metamorph attacks or blocks, target opponent reveals cards from the top of their library until they reveal a creature card. Nascent Metamorph becomes a copy of that card until end of turn. Then that player puts all cards revealed this way on the bottom of their library in a random order.

Opulent Palace enters the battlefield tapped.

{T}: Add {B}, {G}, or {U}.

Mutate {G}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

{1}, {T}: Look at the top card of your library. If it's a land card, you may put it onto the battlefield. If you don't put the card onto the battlefield, put it into your hand.

{T}: Add {G}, {U}, or {R}.

Morph {2} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

When Rattleclaw Mystic is turned face up, add {G}{U}{R}.

Whenever another creature enters the battlefield under your control, you may have Renegade Doppelganger become a copy of that creature until end of turn. (If it does, it loses this ability for the rest of the turn.)

You may have Sakashima the Impostor enter the battlefield as a copy of any creature on the battlefield, except its name is Sakashima the Impostor, it's legendary in addition to its other types, and it has "{2}{U}{U}: Return this creature to its owner's hand at the beginning of the next end step."

Flash

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)

You may have Sakashima's Protege enter the battlefield as a copy of any permanent that entered the battlefield this turn.

Savage Lands enters the battlefield tapped.

{T}: Add {B}, {R}, or {G}.

Enchant land

Enchanted land has "{T}: Add two mana of any one color."

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

Search your library for up to two Forest cards, put them onto the battlefield, then shuffle.

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

Smoldering Marsh enters the battlefield tapped unless you control two or more basic lands.

Enchant creature

You control enchanted creature.

Discard two cards: Soul Ransom's controller sacrifices it, then draws two cards. Only your opponents may activate this ability.

Flying

When Sower of Temptation enters the battlefield, gain control of target creature for as long as Sower of Temptation remains on the battlefield.

Enchant creature

You control enchanted creature.

Enchanted creature gets +2/+2 and has flying.

Enchant artifact

You control enchanted artifact.

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

As Steam Vents enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

({T}: Add {R} or {G}.)

As Stomping Ground enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Flash

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

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

Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {B}.)

Defender, hexproof

{T}: Add one mana of any color.

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)

Enchant permanent

You control enchanted permanent.

Creatures you control have haste.

Whenever a creature with power 4 or greater enters the battlefield under your control, you may draw a card.

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Whenever Thada Adel, Acquisitor deals combat damage to a player, search that player's library for an artifact card and exile it. Then that player shuffles. Until end of turn, you may play that card.

{T}: Add {C}{C}{C}.

{T}: Add {B}, {G}, or {U}.

{1}{B}, Sacrifice a creature: You gain 1 life and draw a card.

You may cast spells as though they had flash.

Enchant land

When Verdant Haven enters the battlefield, you gain 2 life.

Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.

{4}{U}: Tap target creature without flying.

As Vesuvan Shapeshifter enters the battlefield or is turned face up, you may choose another creature on the battlefield. If you do, until Vesuvan Shapeshifter is turned face down, it becomes a copy of that creature, except it has "At the beginning of your upkeep, you may turn this creature face down."

Morph {1}{U}

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}

Enchant permanent

When Volition Reins enters the battlefield, if enchanted permanent is tapped, untap it.

You control enchanted permanent.

At the beginning of combat on your turn, put a -1/-1 counter on up to one target creature.

{1}: Until your next turn, Volrath, the Shapestealer becomes a copy of target creature with a counter on it, except it's 7/5 and it has this ability.

You may have Wall of Stolen Identity enter the battlefield as a copy of any creature on the battlefield, except it's a Wall in addition to its other types and has defender. When you do, tap the copied creature and it doesn't untap during its controller's untap step for as long as you control Wall of Stolen Identity.

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

As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

Indestructible

As long as your devotion to red and green is less than seven, Xenagos isn't a creature.

At the beginning of combat on your turn, another target creature you control gains haste and gets +X/+X until end of turn, where X is that creature's power.

Enchant creature

You control enchanted creature.

Enchanted creature gets +2/+2 and has trample.

Trample

Whenever Yidris, Maelstrom Wielder deals combat damage to a player, as you cast spells from your hand this turn, they gain cascade. (When you cast the spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom of your library in a random order.)