Dismal Backwater

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

Clawing Torment

Enchant artifact or creature
As long as enchanted permanent is a creature, it gets -1/-1 and can't block.
Enchanted permanent has "At the beginning of your upkeep, you lose 1 life."

Uncharted Haven

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

March of Wretched Sorrow

As an additional cost to cast this spell, you may exile any number of black cards from your hand. This spell costs {2} less to cast for each card exiled this way.
March of Wretched Sorrow deals X damage to target creature or planeswalker and you gain X life.

Moon-Circuit Hacker

Ninjutsu {U} ({U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Moon-Circuit Hacker deals combat damage to a player, you may draw a card. If you do, discard a card unless Moon-Circuit Hacker entered this turn.

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.

Essence Capture

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

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 artifact: Add one mana of any color.")

Swamp

Dokuchi Silencer

Ninjutsu {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Dokuchi Silencer deals combat damage to a player, you may discard a creature card. When you do, destroy target creature or planeswalker that player controls.

Moonsnare Specialist

Ninjutsu {2}{U} ({2}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
When Moonsnare Specialist enters, return up to one target creature to its owner's hand.

Futurist Operative

As long as Futurist Operative is tapped, it's a Human Citizen with base power and toughness 1/1 and can't be blocked.
{2}{U}: Untap Futurist Operative.

Mukotai Ambusher

Ninjutsu {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Lifelink

Disruption Protocol

As an additional cost to cast this spell, tap an untapped artifact you control or pay {1}.
Counter target spell.

Enormous Energy Blade

Equipped creature gets +4/+0.
Whenever Enormous Energy Blade becomes attached to a creature, tap that creature.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Kaito's Pursuit

Target player discards two cards. Ninjas and Rogues you control gain menace until end of turn. (They can't be blocked except by two or more creatures.)

Guardians of Oboro

Defender
Modified creatures you control can attack as though they didn't have defender. (Equipment, Auras you control, and counters are modifications.)

Network Disruptor

Flying
When Network Disruptor enters, tap target permanent.

Nezumi Prowler

Ninjutsu {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
When Nezumi Prowler enters, target creature you control gains deathtouch and lifelink until end of turn.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Inkrise Infiltrator

Flying
{3}{B}: Inkrise Infiltrator gets +2/+2 until end of turn.

Twisted Embrace

Enchant artifact or creature you control
When Twisted Embrace enters, destroy target creature or planeswalker an opponent controls.
As long as enchanted permanent is a creature, it gets +1/+1.