Ancient Silver Dragon

Flying
Whenever this creature deals combat damage to a player, roll a d20. Draw cards equal to the result. You have no maximum hand size for the rest of the game.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Mist-Cloaked Herald

Thousand-Faced Shadow

Ninjutsu {2}{U}{U} ({2}{U}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Flying
When this creature enters from your hand, if it's attacking, create a token that's a copy of another target attacking creature. The token enters tapped and attacking.

Blightsteel Colossus

Trample, infect, indestructible
If Blightsteel Colossus would be put into a graveyard from anywhere, reveal Blightsteel Colossus and shuffle it into its owner's library instead.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Dismal Backwater

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {B}.

Rune-Scarred Demon

Flying
When this creature enters, search your library for a card, put it into your hand, then shuffle.

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.)

Triton Shorestalker

Callidus Assassin

Flash
Polymorphine — You may have this creature enter tapped as a copy of any creature on the battlefield, except it has "When this creature enters, destroy up to one other target creature with the same name as this creature."

Sheoldred, Whispering One

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
At the beginning of your upkeep, return target creature card from your graveyard to the battlefield.
At the beginning of each opponent's upkeep, that player sacrifices a creature of their choice.

Peregrine Drake

Flying
When this creature enters, untap up to five lands.

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.")

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Satoru Umezawa

Whenever you activate a ninjutsu ability, look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. This ability triggers only once each turn.
Each creature card in your hand has ninjutsu {2}{U}{B}.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Swamp

Prosperous Thief

Ninjutsu {1}{U} ({1}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever one or more Ninja or Rogue creatures you control deal combat damage to a player, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Biting-Palm Ninja

Ninjutsu {2}{B}
This creature enters with a menace counter on it.
Whenever this creature deals combat damage to a player, you may remove a menace counter from it. When you do, that player reveals their hand and you choose a nonland card from it. Exile that card.

Thought Vessel

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

Oubliette

When this enchantment enters, target creature phases out until this enchantment leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

Counterspell

Cunning Evasion

Whenever a creature you control becomes blocked, you may return it to its owner's hand.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Snap

Return target creature to its owner's hand. Untap up to two lands.

Sol Ring

Faerie Mastermind

Flash
Flying
Whenever an opponent draws their second card each turn, you draw a card.
{3}{U}: Each player draws a card.

Filter Out

Return all noncreature, nonland permanents to their owners' hands.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Kaito, Dancing Shadow

Whenever one or more creatures you control deal combat damage to a player, you may return one of them to its owner's hand. If you do, you may activate loyalty abilities of Kaito twice this turn rather than only once.
+1: Up to one target creature can't attack or block until your next turn.
0: Draw a card.
−2: Create a 2/2 colorless Drone artifact creature token with deathtouch and "When this token leaves the battlefield, each opponent loses 2 life and you gain 2 life."

Baleful Strix

Flying, deathtouch
When this creature enters, draw a card.

Negate

Nezahal, Primal Tide

This spell can't be countered.
You have no maximum hand size.
Whenever an opponent casts a noncreature spell, draw a card.
Discard three cards: Exile Nezahal. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

Demon of Loathing

Flying, trample
Whenever this creature deals combat damage to a player, that player sacrifices a creature of their choice.

Infernal Grasp

Destroy target creature. You lose 2 life.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Invisible Stalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
This creature can't be blocked.

Silver-Fur Master

Ninjutsu {U}{B} ({U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Ninjutsu abilities you activate cost {1} less to activate.
Other Ninja and Rogue creatures you control get +1/+1.

Great Whale

When this creature enters, untap up to seven lands.

Archpriest of Shadows

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following abilities until end of turn.)
Deathtouch
Whenever this creature deals combat damage to a player or battle, return target creature card from your graveyard to the battlefield.

Dimir Signet

Fallen Shinobi

Ninjutsu {2}{U}{B} ({2}{U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, that player exiles the top two cards of their library. Until end of turn, you may play those cards without paying their mana costs.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Command Tower

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

Archon of Cruelty

Flying
Whenever this creature enters or attacks, target opponent sacrifices a creature or planeswalker of their choice, discards a card, and loses 3 life. You draw a card and gain 3 life.

It That Betrays

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)
Whenever an opponent sacrifices a nontoken permanent, put that card onto the battlefield under your control.

Silent-Blade Oni

Ninjutsu {4}{U}{B} ({4}{U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, look at that player's hand. You may cast a spell from among those cards without paying its mana cost.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Quicksilver Gargantuan

You may have this creature enter as a copy of any creature on the battlefield, except it's 7/7.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Rogue Class

(Gain the next level as a sorcery to add its ability.)
Whenever a creature you control deals combat damage to a player, exile the top card of that player's library face down. You may look at it for as long as it remains exiled.
{1}{U}{B}: Level 2
Creatures you control have menace.
{2}{U}{B}: Level 3
You may play cards exiled with this Class, and you may spend mana as though it were mana of any color to cast those spells.

Slither Blade

Gingerbrute

Haste (This creature can attack and {T} as soon as it comes under your control.)
{1}: This creature can't be blocked this turn except by creatures with haste.
{2}, {T}, Sacrifice this creature: You gain 3 life.

Choked Estuary

As this land enters, you may reveal an Island or Swamp card from your hand. If you don't, this land enters tapped.
{T}: Add {U} or {B}.

Tidal Force

At the beginning of each upkeep, you may tap or untap target permanent.

Island

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Ornithopter

Waterfront District

This land enters tapped.
{T}: Add {U} or {B}.
{2}{U}{B}, {T}, Sacrifice this land: Draw a card.

Sunken Hollow

({T}: Add {U} or {B}.)
This land enters tapped unless you control two or more basic lands.

Darkwater Catacombs

Go for the Throat

Crystal Grotto

When this land enters, scry 1.
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Network Disruptor

Flying
When this creature enters, tap target permanent.

Grazilaxx, Illithid Scholar

Whenever a creature you control becomes blocked, you may return it to its owner's hand.
Whenever one or more creatures you control deal combat damage to a player, draw a card.

Alora, Merry Thief

Whenever you attack, up to one target attacking creature can't be blocked this turn. Return that creature to its owner's hand at the beginning of the next end step.
Choose a Background (You can have a Background as a second commander.)

Ringsight

The Ring tempts you. Search your library for a card that shares a color with a legendary creature you control, reveal it, put it into your hand, then shuffle.

Changeling Outcast

Changeling (This card is every creature type.)
This creature can't block and can't be blocked.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Wonder

Flying
As long as this card is in your graveyard and you control an Island, creatures you control have flying.

Toxrill, the Corrosive

At the beginning of each end step, put a slime counter on each creature you don't control.
Creatures you don't control get -1/-1 for each slime counter on them.
Whenever a creature you don't control with a slime counter on it dies, create a 1/1 black Slug creature token.
{U}{B}, Sacrifice a Slug: Draw a card.

Jin-Gitaxias, Core Augur

Flash
At the beginning of your end step, draw seven cards.
Each opponent's maximum hand size is reduced by seven.

Mindleech Mass

Trample
Whenever this creature deals combat damage to a player, you may look at that player's hand. If you do, you may cast a spell from among those cards without paying its mana cost.