Book of Rass

Toy Boat

Cumulative upkeep—Say "Toy Boat" quickly. (At the beginning of your upkeep, put an age counter on Toy Boat, then sacrifice it unless you say "Toy Boat" once for each age counter on it—without pausing between or fumbling it.)

Sneak Attack

{R}: You may put a creature card from your hand onto the battlefield. That creature gains haste. Sacrifice the creature at the beginning of the next end step.

Descent into Avernus

At the beginning of your upkeep, put two descent counters on Descent into Avernus. Then each player creates X Treasure tokens and Descent into Avernus deals X damage to each player, where X is the number of descent counters on Descent into Avernus.

Lim-Dûl's Vault

Look at the top five cards of your library. As many times as you choose, you may pay 1 life, put those cards on the bottom of your library in any order, then look at the top five cards of your library. Then shuffle and put the last cards you looked at this way on top in any order.

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Bronze Calendar

Spells you cast cost {1} less to cast.
You must speak in a voice other than your normal voice.
When you speak in your normal voice, sacrifice Bronze Calendar.

B.O.B. (Bevy of Beebles)

As B.O.B. enters, create four 1/1 blue Beeble creature tokens.
The number of loyalty counters on B.O.B. is equal to the number of Beebles you control. (Create or sacrifice Beebles whenever B.O.B. gains or loses loyalty.)
+1: Up to X target Beebles can't be blocked this turn, where X is the number of cards in your hand.
−1: Draw a card.

Arco-Flagellant

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Arco-Flagellant can't block.
Endurant — Pay 3 life: Arco-Flagellant gains indestructible until end of turn.

Rocket-Powered Turbo Slug

Super haste (This may attack the turn before you cast it. (You may put this card from your hand onto the battlefield tapped and attacking during your declare attackers step. If you do, you lose the game at the beginning of your next turn's end step unless you pay this card's mana cost during that turn.))

Exploration

You may play an additional land on each of your turns.

Jack-in-the-Mox

{T}: Roll a six-sided die. This ability has the indicated effect.
1 — Sacrifice Jack-in-the-Mox and you lose 5 life.
2 — Add {W}.
3 — Add {U}.
4 — Add {B}.
5 — Add {R}.
6 — Add {G}.

Gemstone Array

{2}: Put a charge counter on Gemstone Array.
Remove a charge counter from Gemstone Array: Add one mana of any color.

Lurking Predators

Whenever an opponent casts a spell, reveal the top card of your library. If it's a creature card, put it onto the battlefield. Otherwise, you may put that card on the bottom of your library.

Contagion

You may pay 1 life and exile a black card from your hand rather than pay this spell's mana cost.
Distribute two -2/-1 counters among one or two target creatures.

The Cheese Stands Alone

When you control no permanents other than The Cheese Stands Alone and have no cards in hand, you win the game.

Siege Elemental

Trample
Untapped creatures can't block.
Tapped creatures can block.

Chaos Orb

{1}, {T}: If Chaos Orb is on the battlefield, flip Chaos Orb onto the battlefield from a height of at least one foot. If Chaos Orb turns over completely at least once during the flip, destroy all nontoken permanents it touches. Then destroy Chaos Orb.

Mindbreak Trap

If an opponent cast three or more spells this turn, you may pay {0} rather than pay this spell's mana cost.
Exile any number of target spells.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

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.

Channel

Until end of turn, any time you could activate a mana ability, you may pay 1 life. If you do, add {C}.

In Garruk's Wake

Destroy all creatures you don't control and all planeswalkers you don't control.

Scissors Lizard

Creatures named Paper Tiger can't attack or block.

Bolas's Citadel

You may look at the top card of your library any time.
You may play lands and cast spells from the top of your library. If you cast a spell this way, pay life equal to its mana value rather than pay its mana cost.
{T}, Sacrifice ten nonland permanents: Each opponent loses 10 life.

Your Wish Is My Command

You may cast an instant or sorcery spell from your sideboard. If you cast a modal spell this way, you may choose an additional mode. (A modal spell lets you choose one or more modes from a bulleted list.)

Censorship

As Censorship enters, choose a word.
Whenever a player says the chosen word, Censorship deals 2 damage to that player.

Paper Tiger

Creatures named Rock Lobster can't attack or block.

Abstruse Appropriation

Devoid (This card has no color.)
Exile target nonland permanent. You may cast that card for as long as it remains exiled, and you may spend colorless mana as though it were mana of any color to cast that spell.

Archfiend of Despair

Flying
Your opponents can't gain life.
At the beginning of each end step, each opponent loses life equal to the life that player lost this turn. (Damage causes loss of life.)

Free-for-All

When Free-for-All enters, exile all creatures face down.
At the beginning of each player's upkeep, that player chooses a card exiled with Free-for-All at random and puts it onto the battlefield.
When Free-for-All leaves the battlefield, put all cards exiled with it into their owners' graveyards.

Cheatyface

If Cheatyface is in your hand, you may sneak Cheatyface onto the battlefield. If an opponent catches you right away, that player may exile Cheatyface.
Flying

Chromatic Lantern

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

Vraska, Betrayal's Sting

Compleated ({B/P} can be paid with {B} or 2 life. If life was paid, this planeswalker enters with two fewer loyalty counters.)
0: You draw a card and you lose 1 life. Proliferate.
−2: Target creature becomes a Treasure artifact with "{T}, Sacrifice this artifact: Add one mana of any color" and loses all other card types and abilities.
−9: If target player has fewer than nine poison counters, they get a number of poison counters equal to the difference.

Time Vault

Time Vault enters tapped.
Time Vault doesn't untap during your untap step.
If you would begin your turn while Time Vault is tapped, you may skip that turn instead. If you do, untap Time Vault.
{T}: Take an extra turn after this one.

Decomposition

Enchant black creature
Enchanted creature has "Cumulative upkeep—Pay 1 life." (At the beginning of its controller's upkeep, that player puts an age counter on it, then sacrifices it unless they pay its upkeep cost for each age counter on it.)
When enchanted creature dies, its controller loses 2 life.

The One Ring

Indestructible
When The One Ring enters, if you cast it, you gain protection from everything until your next turn.
At the beginning of your upkeep, you lose 1 life for each burden counter on The One Ring.
{T}: Put a burden counter on The One Ring, then draw a card for each burden counter on The One Ring.

Mox Poison

{T}: Add one mana of any color. You get two poison counters.

March of Swirling Mist

As an additional cost to cast this spell, you may exile any number of blue cards from your hand. This spell costs {2} less to cast for each card exiled this way.
Up to X target creatures phase out. (While they're phased out, they're treated as though they don't exist. Each one phases in before its controller untaps during their next untap step.)

Celestial Dawn

Lands you control are Plains.
Nonland permanents you control are white. The same is true for spells you control and nonland cards you own that aren't on the battlefield.
You may spend white mana as though it were mana of any color. You may spend other mana only as though it were colorless mana.

Mana Abundance

If a player would add mana, instead all players add that mana.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Apple of Eden, Isu Relic

{T}, Pay 4 life, Sacrifice Apple of Eden: Look at target opponent's hand and exile those cards face down. You may play those cards this turn, and mana of any type can be spent to cast them. Until end of turn, whenever you play a land or cast a spell this way, its owner draws a card. At the beginning of the next end step, return the exiled cards to their owner's hand. Activate only as a sorcery.

Command the Chaff

Look at target opponent's sideboard. You may cast a card from that sideboard without paying its mana cost.
Exile Command the Chaff.

Aether Storm

Creature spells can't be cast.
Pay 4 life: Destroy Aether Storm. It can't be regenerated. Any player may activate this ability.

Mana Screw

{1}: Flip a coin. If you win the flip, add {C}{C}. Activate only as an instant.

Rock Lobster

Creatures named Scissors Lizard can't attack or block.

Black Market Connections

At the beginning of your first main phase, choose one or more —
• Sell Contraband — Create a Treasure token. You lose 1 life.
• Buy Information — Draw a card. You lose 2 life.
• Hire a Mercenary — Create a 3/2 colorless Shapeshifter creature token with changeling. You lose 3 life. (It has every creature type.)