The Ninja way

Kicker {3} (You may pay an additional {3} as you cast this spell.)

Aether Figment can't be blocked.

If Aether Figment was kicked, it enters the battlefield with two +1/+1 counters on it.

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Bad River enters the battlefield tapped.

{T}, Sacrifice Bad River: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token that's a copy of that creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Equip {4}

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Blighted Agent can't be blocked.

Cephalid Pathmage can't be blocked.

{T}, Sacrifice Cephalid Pathmage: Target creature can't be blocked this turn.

Equipped creature has first strike, trample, and haste.

Equip {1}

As Choked Estuary enters the battlefield, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters the battlefield tapped.

{T}: Add {U} or {B}.

Creeping Tar Pit enters the battlefield tapped.

{T}: Add {U} or {B}.

{1}{U}{B}: Creeping Tar Pit becomes a 3/2 blue and black Elemental creature until end of turn and can't be blocked this turn. It's still a land.

Shadow (This creature can block or be blocked by only creatures with shadow.)

{1}{B}, {T}: Destroy target creature with shadow.

Shadow (This creature can block or be blocked by only creatures with shadow.)

Whenever a creature with shadow dies, put a +1/+1 counter on Dauthi Ghoul.

Shadow (This creature can block or be blocked by only creatures with shadow.)

Dauthi Horror can't be blocked by white creatures.

Shadow (This creature can block or be blocked by only creatures with shadow.)

{B}{B}, Sacrifice Dauthi Jackal: Destroy target blocking creature.

Shadow (This creature can block or be blocked by only creatures with shadow.)

Shadow (This creature can block or be blocked by only creatures with shadow.)

{1}{B}: Dauthi Mercenary gets +1/+0 until end of turn.

Shadow (This creature can block or be blocked by only creatures with shadow.)

Dauthi Slayer attacks each combat if able.

{T}: Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

Shadow (This creature can block or be blocked by only creatures with shadow.)

Dauthi Warlord's power is equal to the number of creatures with shadow on the battlefield.

Deep-Sea Kraken can't be blocked.

Suspend 9—{2}{U} (Rather than cast this card from your hand, you may pay {2}{U} and exile it with nine time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, cast it without paying its mana cost. It has haste.)

Whenever an opponent casts a spell, if Deep-Sea Kraken is suspended, remove a time counter from it.

Blue creatures you control can't be blocked.

Dimir Aqueduct enters the battlefield tapped.

When Dimir Aqueduct enters the battlefield, return a land you control to its owner's hand.

{T}: Add {U}{B}.

Dimir Guildgate enters the battlefield tapped.

{T}: Add {U} or {B}.

Dimir Infiltrator can't be blocked.

Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

{1}, {T}: Add {U}{B}.

Dismal Backwater enters the battlefield tapped.

When Dismal Backwater enters the battlefield, you gain 1 life.

{T}: Add {U} or {B}.

As Door of Destinies enters the battlefield, choose a creature type.

Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.

Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Shadow (This creature can block or be blocked by only creatures with shadow.)

At the beginning of your upkeep, sacrifice Drifter il-Dal unless you pay {U}.

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.

{T}: Add {U} or {B}.

Escape Artist can't be blocked.

{U}, Discard a card: Return Escape Artist to its owner's hand.

Ferropede can't be blocked.

Whenever Ferropede deals combat damage to a player, you may remove a counter from target permanent.

Bestow {5}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)

Flitterstep Eidolon can't be blocked.

Enchanted creature gets +1/+1 and can't be blocked.

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.)

Equipped creature has vigilance, trample, and haste.

Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

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.

Shadow (This creature can block or be blocked by only creatures with shadow.)

Suspend 2—{1}{U} (Rather than cast this card from your hand, you may pay {1}{U} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, cast it without paying its mana cost. It has haste.)

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.

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

Invisible Stalker can't be blocked.

({T}: Add {U}.)

Jwar Isle Refuge enters the battlefield tapped.

When Jwar Isle Refuge enters the battlefield, you gain 1 life.

{T}: Add {U} or {B}.

When Keeper of Keys enters the battlefield, you become the monarch.

At the beginning of your upkeep, if you're the monarch, creatures you control can't be blocked this turn.

Latch Seeker can't be blocked.

Shadow (This creature can block or be blocked by only creatures with shadow.)

Whenever Looter il-Kor deals damage to an opponent, draw a card, then discard a card.

Whenever a nontoken creature enters the battlefield under your control, you may pay {2}. If you do, create a token that's a copy of that creature, except it has haste and "At the beginning of the end step, sacrifice this permanent."

Mist-Cloaked Herald can't be blocked.

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.

Morphic Pool enters the battlefield tapped unless you have two or more opponents.

{T}: Add {U} or {B}.

Haste

Shadow (This creature can block or be blocked by only creatures with shadow.)

Whenever another creature is put into your graveyard from the battlefield, you may pay {B}. If you do, return Nether Traitor from your graveyard to the battlefield.

Neurok Invisimancer can't be blocked.

When Neurok Invisimancer enters the battlefield, target creature can't be blocked this turn.

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.

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)

As Obelisk of Urd enters the battlefield, choose a creature type.

Creatures you control of the chosen type get +2/+2.

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.

Phantom Warrior can't be blocked.

Equipped creature has haste. (It can attack and {T} no matter when it came under your control.)

At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's red.

Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

River Sneak can't be blocked.

Whenever another Merfolk enters the battlefield under your control, River Sneak gets +1/+1 until end of turn.

Equipped creature gets +1/+1.

Whenever a creature enters the battlefield under your control, you may attach Sai of the Shinobi to it.

Equip {2}

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.

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.

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.

Slither Blade can't be blocked.

Soulsworn Spirit can't be blocked.

When Soulsworn Spirit enters the battlefield, detain target creature an opponent controls. (Until your next turn, that creature can't attack or block and its activated abilities can't be activated.)

Equipped creature gets +1/+1 and has haste.

Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Shadow (This creature can block or be blocked by only creatures with shadow.)

Whenever Stronghold Rats deals combat damage to a player, each player discards a card.

({T}: Add {U} or {B}.)

Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {B}.)

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)

Equip {1}

Talas Warrior can't be blocked.

Temple of Deceit enters the battlefield tapped.

When Temple of Deceit enters the battlefield, scry 1.

{T}: Add {U} or {B}.

Shadow (This creature can block or be blocked by only creatures with shadow.)

{U}: Put Thalakos Mistfolk on top of its owner's library.

Shadow (This creature can block or be blocked by only creatures with shadow.)

Discard a card: Return Thalakos Scout to its owner's hand.

Shadow (This creature can block or be blocked by only creatures with shadow.)

When Thalakos Seer leaves the battlefield, draw a card.

Shadow (This creature can block or be blocked by only creatures with shadow.)

Indestructible

As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

At the beginning of your upkeep, scry 1.

{1}{U}: Target creature you control can't be blocked this turn.

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.

Tormented Soul can't block and can't be blocked.

Triton Shorestalker can't be blocked.

As Vanquisher's Banner enters the battlefield, choose a creature type.

Creatures you control of the chosen type get +1/+1.

Whenever you cast a creature spell of the chosen type, draw a card.

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.

({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.

When Whirler Rogue enters the battlefield, create two 1/1 colorless Thopter artifact creature tokens with flying.

Tap two untapped artifacts you control: Target creature can't be blocked this turn.

Commander ninjutsu {U}{B} ({U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand or the command zone tapped and attacking.)

Whenever a Ninja you control deals combat damage to a player, reveal the top card of your library and put that card into your hand. Each opponent loses life equal to that card's mana value.