Jailbreak Scheme

Spree (Choose one or more additional costs.)
+ {3} — Put a +1/+1 counter on target creature. It can't be blocked this turn.
+ {2} — Target artifact or creature's owner puts it on their choice of the top or bottom of their library.

Forlorn Flats

Forlorn Flats enters tapped.
When Forlorn Flats enters, it deals 1 damage to target opponent.
{T}: Add {W} or {B}.

Gila Courser

Whenever Gila Courser attacks while saddled, exile the top card of your library. Until the end of your next turn, you may play that card.
Saddle 1 (Tap any number of other creatures you control with total power 1 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Reach for the Sky

Flash
Enchant creature
Enchanted creature gets +3/+2 and has reach.
When Reach for the Sky is put into a graveyard from the battlefield, draw a card.

Emergent Haunting

At the beginning of your end step, if you haven't cast a spell from your hand this turn and Emergent Haunting isn't a creature, it becomes a 3/3 Spirit creature with flying in addition to its other types.
{2}{U}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Great Train Heist

Spree (Choose one or more additional costs.)
+ {2}{R} — Untap all creatures you control. If it's your combat phase, there is an additional combat phase after this phase.
+ {2} — Creatures you control get +1/+0 and gain first strike until end of turn.
+ {R} — Choose target opponent. Whenever a creature you control deals combat damage to that player this turn, create a tapped Treasure token.

Lassoed by the Law

When Lassoed by the Law enters, exile target nonland permanent an opponent controls until Lassoed by the Law leaves the battlefield.
When Lassoed by the Law enters, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."

Creosote Heath

Creosote Heath enters tapped.
When Creosote Heath enters, it deals 1 damage to target opponent.
{T}: Add {G} or {W}.

Ride Down

Destroy target blocking creature. Creatures that were blocked by that creature this combat gain trample until end of turn.

Return the Favor

Spree (Choose one or more additional costs.)
+ {1} — Copy target instant spell, sorcery spell, activated ability, or triggered ability. You may choose new targets for the copy.
+ {1} — Change the target of target spell or ability with a single target.

Jem Lightfoote, Sky Explorer

Flying, vigilance
At the beginning of your end step, if you haven't cast a spell from your hand this turn, draw a card.

Discerning Peddler

When Discerning Peddler enters, you may discard a card. If you do, draw a card.

Gold Rush

Create a Treasure token. Until end of turn, up to one target creature gets +2/+2 for each Treasure you control.

Assimilation Aegis

When Assimilation Aegis enters, exile up to one target creature until Assimilation Aegis leaves the battlefield.
Whenever Assimilation Aegis becomes attached to a creature, for as long as Assimilation Aegis remains attached to it, that creature becomes a copy of a creature card exiled with Assimilation Aegis.
Equip {2}

Lonely Arroyo

Lonely Arroyo enters tapped.
When Lonely Arroyo enters, it deals 1 damage to target opponent.
{T}: Add {W} or {U}.

Lazav, Familiar Stranger

Whenever you commit a crime, put a +1/+1 counter on Lazav, Familiar Stranger. Then you may exile a card from a graveyard. If a creature card was exiled this way, you may have Lazav become a copy of that card until end of turn. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Forest

Raucous Entertainer

{1}, {T}: Put a +1/+1 counter on each creature you control that entered this turn.

Stop Cold

Flash
Enchant artifact or creature
When Stop Cold enters, tap enchanted permanent.
Enchanted permanent loses all abilities and doesn't untap during its controller's untap step.

Ankle Biter

Worldwalker Helm

If you would create one or more artifact tokens, instead create those tokens plus an additional Map token. (It's an artifact with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")
{1}{U}, {T}: Create a token that's a copy of target artifact token you control.

Sterling Keykeeper

Irascible Wolverine

When Irascible Wolverine enters, exile the top card of your library. Until end of turn, you may play that card.
Plot {2}{R} (You may pay {2}{R} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Outlaws' Fury

Creatures you control get +2/+0 until end of turn. If you control an outlaw, exile the top card of your library. Until the end of your next turn, you may play that card. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)

Drover Grizzly

Whenever Drover Grizzly attacks while saddled, creatures you control gain trample until end of turn.
Saddle 1 (Tap any number of other creatures you control with total power 1 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Pitiless Carnage

Sacrifice any number of permanents you control, then draw that many cards.
Plot {1}{B}{B} (You may pay {1}{B}{B} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Blacksnag Buzzard

Flying
Blacksnag Buzzard enters with a +1/+1 counter on it if a creature died this turn.
Plot {1}{B} (You may pay {1}{B} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Kraum, Violent Cacophony

Flying
Whenever you cast your second spell each turn, put a +1/+1 counter on Kraum, Violent Cacophony and draw a card.

Thornado

Destroy target creature with flying.
Cycling {1}{G} ({1}{G}, Discard this card: Draw a card.)

Tomb Trawler

{2}: Put target card from your graveyard on the bottom of your library.

Rooftop Assassin

Flash
Flying, lifelink
When Rooftop Assassin enters, destroy target creature an opponent controls that was dealt damage this turn.

Harrier Strix

Flying
When Harrier Strix enters, tap target permanent.
{2}{U}: Draw a card, then discard a card.

Corrupted Conviction

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

Sterling Supplier

Flying
When Sterling Supplier enters, put a +1/+1 counter on another target creature you control.

Trained Arynx

Whenever Trained Arynx attacks while saddled, it gains first strike until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Visage Bandit

You may have Visage Bandit enter as a copy of a creature you control, except it's a Shapeshifter Rogue in addition to its other types.
Plot {2}{U} (You may pay {2}{U} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Prairie Dog

Lifelink
At the beginning of your end step, if you haven't cast a spell from your hand this turn, put a +1/+1 counter on Prairie Dog.
{4}{W}: Until end of turn, if you would put one or more +1/+1 counters on a creature you control, put that many plus one +1/+1 counters on it instead.

Metamorphic Blast

Spree (Choose one or more additional costs.)
+ {1} — Until end of turn, target creature becomes a white Rabbit with base power and toughness 0/1.
+ {3} — Target player draws two cards.

Treasure Dredger

{1}, {T}, Pay 1 life: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Vengeful Townsfolk

Whenever one or more other creatures you control die, put a +1/+1 counter on Vengeful Townsfolk.

Peerless Ropemaster

When Peerless Ropemaster enters, return up to one target tapped creature to its owner's hand.

Loan Shark

When Loan Shark enters, if you've cast two or more spells this turn, draw a card.
Plot {3}{U} (You may pay {3}{U} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Bridled Bighorn

Vigilance
Whenever Bridled Bighorn attacks while saddled, create a 1/1 white Sheep creature token.
Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Prickly Pair

When Prickly Pair enters, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."

Annie Flash, the Veteran

Flash
When Annie Flash, the Veteran enters, if you cast it, return target permanent card with mana value 3 or less from your graveyard to the battlefield tapped.
Whenever Annie Flash becomes tapped, exile the top two cards of your library. You may play those cards this turn.

Heartless Pillage

Target opponent discards two cards.
Raid — If you attacked this turn, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Snakeskin Veil

Put a +1/+1 counter on target creature you control. It gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Rush of Dread

Spree (Choose one or more additional costs.)
+ {1} — Target opponent sacrifices half the creatures they control of their choice, rounded up.
+ {2} — Target opponent discards half the cards in their hand, rounded up.
+ {2} — Target opponent loses half their life, rounded up.

Satoru, the Infiltrator

Menace
Whenever Satoru, the Infiltrator and/or one or more other nontoken creatures you control enter, if none of them were cast or no mana was spent to cast them, draw a card.

Abraded Bluffs

Abraded Bluffs enters tapped.
When Abraded Bluffs enters, it deals 1 damage to target opponent.
{T}: Add {R} or {W}.

Redrock Sentinel

Defender
{2}, {T}, Sacrifice a land: Draw a card and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Outlaw Stitcher

When Outlaw Stitcher enters, create a 2/2 blue and black Zombie Rogue creature token, then put two +1/+1 counters on that token for each spell you've cast this turn other than the first.
Plot {4}{U} (You may pay {4}{U} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Boneyard Desecrator

Menace
{1}{B}, Sacrifice another creature: Put a +1/+1 counter on Boneyard Desecrator. If an outlaw was sacrificed this way, create a Treasure token. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)

Servant of the Stinger

Deathtouch
Whenever Servant of the Stinger deals combat damage to a player, if you've committed a crime this turn, you may sacrifice Servant of the Stinger. If you do, search your library for a card, put it into your hand, then shuffle. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Throw from the Saddle

Target creature you control gets +1/+1 until end of turn. Put a +1/+1 counter on it instead if it's a Mount. Then it deals damage equal to its power to target creature you don't control.

Vault Plunderer

When Vault Plunderer enters, target player draws a card and loses 1 life.

Reckless Lackey

First strike, haste
{2}{R}, Sacrifice Reckless Lackey: Draw a card and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Spinewoods Paladin

Trample
When Spinewoods Paladin enters, you gain 3 life.
Plot {3}{G} (You may pay {3}{G} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Cactarantula

This spell costs {1} less to cast if you control a Desert.
Reach
Whenever Cactarantula becomes the target of a spell or ability an opponent controls, you may draw a card.

Failed Fording

Return target nonland permanent to its owner's hand. If you control a Desert, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Lilah, Undefeated Slickshot

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast a multicolored instant or sorcery spell from your hand, exile that spell instead of putting it into your graveyard as it resolves. If you do, it becomes plotted. (You may cast it as a sorcery on a later turn without paying its mana cost.)

Overzealous Muscle

Whenever you commit a crime during your turn, Overzealous Muscle gains indestructible until end of turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime. Damage and effects that say "destroy" don't destroy a creature with indestructible.)

Bristling Backwoods

Bristling Backwoods enters tapped.
When Bristling Backwoods enters, it deals 1 damage to target opponent.
{T}: Add {R} or {G}.

Seize the Secrets

This spell costs {1} less to cast if you've committed a crime this turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)
Draw two cards.

Mirage Mesa

Mirage Mesa enters tapped. As it enters, choose a color.
{T}: Add one mana of the chosen color.

Quilled Charger

Whenever Quilled Charger attacks while saddled, it gets +1/+2 and gains menace until end of turn. (It can't be blocked except by two or more creatures.)
Saddle 2 (Tap any number of other creatures you control with total power 2 or more: This Mount becomes saddled until end of turn. Saddle only as a sorcery.)

Rodeo Pyromancers

Whenever you cast your first spell each turn, add {R}{R}.

Sandstorm Verge

{T}: Add {C}.
{3}, {T}: Target creature can't block this turn. Activate only as a sorcery.

Outcaster Greenblade

When Outcaster Greenblade enters, search your library for a basic land card or a Desert card, reveal it, put it into your hand, then shuffle.
Outcaster Greenblade gets +1/+1 for each Desert you control.

Essence Capture

Counter target creature spell. Put a +1/+1 counter on up to one target creature you control.

Tumbleweed Rising

Create an X/X green Elemental creature token, where X is the greatest power among creatures you control.
Plot {2}{G} (You may pay {2}{G} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Decisive Denial

Choose one —
• Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)
• Counter target noncreature spell unless its controller pays {3}.

Breeches, the Blastmaker

Menace
Whenever you cast your second spell each turn, you may sacrifice an artifact. If you do, flip a coin. When you win the flip, copy that spell. You may choose new targets for the copy. When you lose the flip, Breeches, the Blastmaker deals damage equal to that spell's mana value to any target.

Thunder Lasso

When Thunder Lasso enters, attach it to target creature you control.
Equipped creature gets +1/+1.
Whenever equipped creature attacks, tap target creature defending player controls.
Equip {2}

Geyser Drake

Flying
During turns other than yours, spells you cast cost {1} less to cast.

Hardbristle Bandit

{T}: Add one mana of any color.
Whenever you commit a crime, untap Hardbristle Bandit. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Make Your Own Luck

Look at the top three cards of your library. You may exile a nonland card from among them. If you do, it becomes plotted. Put the rest into your hand. (You may cast it as a sorcery on a later turn without paying its mana cost.)

Steer Clear

Steer Clear deals 2 damage to target attacking or blocking creature. Steer Clear deals 4 damage to that creature instead if you controlled a Mount as you cast this spell.