Mindleech Mass

Trample
Whenever Mindleech Mass 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.

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 Fallen Shinobi 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.

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.

Night's Whisper

Morphic Pool

Morphic Pool enters the battlefield tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Talisman of Dominance

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

Sakashima's Student

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.)
You may have Sakashima's Student enter the battlefield as a copy of any creature on the battlefield, except it's a Ninja in addition to its other creature types.

Dimir Keyrune

{T}: Add {U} or {B}.
{U}{B}: Dimir Keyrune becomes a 2/2 blue and black Horror artifact creature until end of turn and can't be blocked this turn.

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

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.

Mist-Cloaked Herald

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}.

Dimir Signet

Feed the Swarm

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

Ornithopter

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

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, Primal Tide. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

Negate

Wrexial, the Risen Deep

Islandwalk, swampwalk (This creature can't be blocked as long as defending player controls an Island or a Swamp.)
Whenever Wrexial, the Risen Deep deals combat damage to a player, you may cast target instant or sorcery card from that player's graveyard without paying its mana cost. If that spell would be put into a graveyard, exile it instead.

Whispersilk Cloak

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

Shipwreck Marsh

Shipwreck Marsh enters the battlefield tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Toxic Deluge

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

Rogue's Passage

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

Drowned Catacomb

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Changeling Outcast

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

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Windfall

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

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 Silent-Blade Oni 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.

Swamp

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.

Resculpt

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

Invisible Stalker

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

Baleful Strix

Flying, deathtouch
When Baleful Strix enters the battlefield, draw a card.

Ingenious Prodigy

Skulk (This creature can't be blocked by creatures with greater power.)
Ingenious Prodigy enters the battlefield with X +1/+1 counters on it.
At the beginning of your upkeep, if Ingenious Prodigy has one or more +1/+1 counters on it, you may remove a +1/+1 counter from it. If you do, draw a card.

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.

Gudul Lurker

Gudul Lurker can't be blocked.
Megamorph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)

Watery Grave

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

Island

Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.