Assassinate

Sudden Death

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Target creature gets -4/-4 until end of turn.

Higure, the Still Wind

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.)
Whenever Higure, the Still Wind deals combat damage to a player, you may search your library for a Ninja card, reveal it, put it into your hand, then shuffle.
{2}: Target Ninja creature can't be blocked this turn.

Mistform Ultimus

Mistform Ultimus is every creature type (even if this card isn't on the battlefield).

Smoke

Players can't untap more than one creature during their untap steps.

Invisibility

Enchant creature
Enchanted creature can't be blocked except by Walls.

Swamp

Deserted Temple

{T}: Add {C}.
{1}, {T}: Untap target land.

Shuriken

Equipped creature has "{T}, Unattach Shuriken: Shuriken deals 2 damage to target creature. That creature's controller gains control of Shuriken unless it was unattached from a Ninja."
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

City of Shadows

{T}, Exile a creature you control: Put a storage counter on City of Shadows.
{T}: Add {C} for each storage counter on City of Shadows.

Throat Slitter

Ninjutsu {2}{B} ({2}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Throat Slitter deals combat damage to a player, destroy target nonblack creature that player controls.

Blinding Powder

Equipped creature has "Unattach Blinding Powder: Prevent all combat damage that would be dealt to this creature this turn."
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Skullsnatcher

Ninjutsu {B} ({B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Skullsnatcher deals combat damage to a player, exile up to two target cards from that player's graveyard.

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.

Kill! Destroy!

Destroy target nonblack creature.
Gotcha — If an opponent says "kill" or "destroy," you may say "Gotcha!" When you do, return Kill! Destroy! from your graveyard to your hand.

Maze of Shadows

{T}: Add {C}.
{T}: Untap target attacking creature with shadow. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Mountain

Cloak of Mists

Enchant creature
Enchanted creature can't be blocked.

Ink-Eyes, Servant of Oni

Ninjutsu {3}{B}{B} ({3}{B}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Ink-Eyes, Servant of Oni deals combat damage to a player, you may put target creature card from that player's graveyard onto the battlefield under your control.
{1}{B}: Regenerate Ink-Eyes.

Death Stroke

Halls of Mist

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Creatures that attacked during their controller's last turn can't attack.

Mistblade Shinobi

Ninjutsu {U} ({U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Mistblade Shinobi deals combat damage to a player, you may return target creature that player controls to its owner's hand.

Vault of Whispers

Argothian Swine

Teleport

Cast this spell only during the declare attackers step.
Target creature can't be blocked this turn.

Duskmantle, House of Shadow

{T}: Add {C}.
{U}{B}, {T}: Target player mills a card.

Defy Gravity

Target creature gains flying until end of turn.
Flashback {U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Okiba-Gang Shinobi

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Okiba-Gang Shinobi deals combat damage to a player, that player discards two cards.

Ninja of the Deep Hours

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 Ninja of the Deep Hours deals combat damage to a player, you may draw a card.

Darkness

Prevent all combat damage that would be dealt this turn.

Lantern-Lit Graveyard

{T}: Add {C}.
{T}: Add {B} or {R}. Lantern-Lit Graveyard doesn't untap during your next untap step.

Ass Whuppin'

Destroy target silver-bordered or acorn permanent in any game you can see from your seat.

Infiltrate

Target creature can't be blocked this turn.

Walker of Secret Ways

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 Walker of Secret Ways deals combat damage to a player, look at that player's hand.
{1}{U}: Return target Ninja you control to its owner's hand. Activate only during your turn.