Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

An Offer You Can't Refuse

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

Stinging Study

You draw X cards and you lose X life, where X is the mana value of a commander you own on the battlefield or in the command zone.

Anguished Unmaking

Exile target nonland permanent. You lose 3 life.

Angel of Jubilation

Flying
Other nonblack creatures you control get +1/+1.
Players can't pay life or sacrifice creatures to cast spells or activate abilities.

Talisman of Progress

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

Praetor's Grasp

Search target opponent's library for a card and exile it face down. Then that player shuffles. You may play that card for as long as it remains exiled.

Village Rites

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

Sol Ring

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Archivist of Oghma

Flash
Whenever an opponent searches their library, you gain 1 life and draw a card.

Fractured Identity

Exile target nonland permanent. Each player other than its controller creates a token that's a copy of it.

Sen Triplets

At the beginning of your upkeep, choose target opponent. This turn, that player can't cast spells or activate abilities and plays with their hand revealed. You may play lands and cast spells from that player's hand this turn.

Deep Gnome Terramancer

Flash
Mold Earth — Whenever one or more lands enter under an opponent's control without being played, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle. Do this only once each turn.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Talisman of Hierarchy

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

Thought Vessel

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

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Containment Priest

Flash
If a nontoken creature would enter and it wasn't cast, exile it instead.

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Fellwar Stone

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

Orcish Bowmasters

Flash
When Orcish Bowmasters enters and whenever an opponent draws a card except the first one they draw in each of their draw steps, Orcish Bowmasters deals 1 damage to any target. Then amass Orcs 1.

Standstill

When a player casts a spell, sacrifice Standstill. If you do, each of that player's opponents draws three cards.

Counterspell

Chromatic Lantern

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

Mana Drain

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

Opposition Agent

Flash
You control your opponents while they're searching their libraries.
While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

Arcane Signet

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

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

In Too Deep

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 creature, planeswalker, or Clue
Enchanted permanent is a colorless Clue artifact with "{2}, Sacrifice this artifact: Draw a card" and loses all other abilities. (It's no longer a creature or planeswalker.)

Talisman of Dominance

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

Void Rend

This spell can't be countered.
Destroy target nonland permanent.

Manascape Refractor

Manascape Refractor enters tapped.
Manascape Refractor has all activated abilities of all lands on the battlefield.
You may spend mana as though it were mana of any color to pay the activation costs of Manascape Refractor's abilities.

Sadistic Sacrament

Kicker {7} (You may pay an additional {7} as you cast this spell.)
Search target player's library for up to three cards, exile them, then that player shuffles. If this spell was kicked, instead search that player's library for up to fifteen cards, exile them, then that player shuffles.

Swan Song

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