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

You may choose not to untap Helm of Possession during your untap step. {2}, {T}, Sacrifice a creature: Gain control of target creature for as long as you control Helm of Possession and Helm of Possession remains tapped.

Imprint — Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with Mimic Vat to its owner's graveyard. {3}, {T}: Create a token that's a copy of a card exiled with Mimic Vat. It gains haste. Exile it at the beginning of the next end step.

The "legend rule" doesn't apply to permanents you control. Each legendary creature you control gets +1/+1. Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

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

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.) When Acidic Slime enters the battlefield, destroy target artifact, enchantment, or land.

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.) If one or more tokens would be created under your control, twice that many of those tokens are created instead.

When Agent of Treachery enters the battlefield, gain control of target permanent. At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

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.

Mutate {5}{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.) Whenever this creature mutates, tap up to X target creatures, where X is the number of times this creature has mutated. Those creatures don't untap during their controller's next untap step.

Flying {T}: Add one mana of any color.

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

Avoidance — Whenever you cast a noncreature spell, exile up to one target nonland permanent you control, then return that card to the battlefield under its owner's control.

Flying The first time you would create one or more tokens during each of your turns, you may instead choose a creature other than Esix, Fractal Bloom and create that many tokens that are copies of that creature.

When Eternal Witness enters the battlefield, you may return target card from your graveyard to your hand.

Changeling (This card is every creature type.) You may have Moritte of the Frost enter the battlefield as a copy of a permanent you control, except it's legendary and snow in addition to its other types and, if it's a creature, it enters with two additional +1/+1 counters on it and has changeling.

Changeling Whenever you cast an instant or sorcery spell, if it targets one or more other permanents you control, create a token that's a copy of one of those permanents. When a spell or ability an opponent controls causes you to discard this card, create a token that's a copy of target permanent.

({U/P} can be paid with either {U} or 2 life.) You may have Phyrexian Metamorph enter the battlefield as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

When Reclamation Sage enters the battlefield, you may destroy target artifact or enchantment.

Flying Landfall — Whenever a land enters the battlefield under your control, you may gain control of target creature for as long as you control Roil Elemental.

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.

You may have Spark Double enter the battlefield as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

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.

Kicker {X}. X can't be 0. (You may pay an additional {X} as you cast this spell.) Flying When Thieving Skydiver enters the battlefield, if it was kicked, gain control of target artifact with mana value X or less. If that artifact is an Equipment, attach it to Thieving Skydiver.

Enchant creature Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control." Totem armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Enchant creature When Colossification enters the battlefield, tap enchanted creature. Enchanted creature gets +20/+20.

Enchant creature Whenever enchanted creature deals damage to an opponent, you may draw a card.

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead. If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Enchant creature At the beginning of your upkeep, create a token that's a copy of enchanted creature.

Whenever an opponent casts their first spell each turn, that player exiles the top card of their library. If it's a nonland card, you may cast it without paying its mana cost.

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

If one or more tokens would be created, twice that many of those tokens are created instead. If one or more +1/+1 counters would be put on a creature, twice that many +1/+1 counters are put on that creature instead.

Enchant creature Enchanted creature gets +2/+0 and has trample. When Rancor is put into a graveyard from the battlefield, return Rancor to its owner's hand.

({G/U} can be paid with either {G} or {U}.) Enchant creature When Shielding Plax enters the battlefield, draw a card. Enchanted creature can't be the target of spells or abilities your opponents control.

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.

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Counter target spell.

Copy target creature spell you control, except it isn't legendary if the spell is legendary. (A copy of a creature spell becomes a token.)

Draw a card. You may put a land card from your hand onto the battlefield.

Choose target nonlegendary creature. The next time one or more creatures or planeswalkers enter the battlefield this turn, they enter as copies of the chosen creature. Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.) Exchange control of target noncreature spell and target creature. Then the spell's controller may choose new targets for it.

Return target creature to its owner's hand. You create a token that's a copy of that creature.

{T}: Add {G}. Channel — {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Botanical Sanctum enters the battlefield tapped unless you control two or fewer other lands. {T}: Add {G} or {U}.

({T}: Add {G} or {U}.) As Breeding Pool enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

{T}: Add {C}. {3}, {T}, Sacrifice a land: Destroy target nonbasic land.

{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.

({T}: Add {G}.)

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island. {T}: Add {G} or {U}.

({T}: Add {U}.)

You have no maximum hand size. {T}: Add {C}.

Simic Growth Chamber enters the battlefield tapped. When Simic Growth Chamber enters the battlefield, return a land you control to its owner's hand. {T}: Add {G}{U}.

Temple of Mystery enters the battlefield tapped. When Temple of Mystery enters the battlefield, scry 1. {T}: Add {G} or {U}.

As Vineglimmer Snarl enters the battlefield, you may reveal a Forest or Island card from your hand. If you don't, Vineglimmer Snarl enters the battlefield tapped. {T}: Add {G} or {U}.

Destroy target artifact or enchantment. You may put a land card from your hand onto the battlefield.

Create a token that's a copy of target non-Frog creature, except it's a 1/1 green Frog. Flashback {3}{G}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Create a token that's a copy of target creature you control, except the token has flying and it isn't legendary.

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Create a token that's a copy of target creature you control. Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Kicker {5} (You may pay an additional {5} as you cast this spell.) Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.

Create a token that's a copy of target creature. Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)