Seven-Tail Mentor

When this creature enters or dies, put a +1/+1 counter on target creature or Vehicle you control.

Selfless Samurai

Whenever a Samurai or Warrior you control attacks alone, it gains lifelink until end of turn.
Sacrifice this creature: Another target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Angelic Benediction

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Whenever a creature you control attacks alone, you may tap target creature.

Blade Historian

Attacking creatures you control have double strike.

Sigiled Paladin

First strike
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Holy Avenger

Equipped creature has double strike.
Whenever equipped creature deals combat damage, you may put an Aura card from your hand onto the battlefield attached to it.
Equip {2}{W}

Kaya's Onslaught

Target creature gets +1/+1 and gains double strike until end of turn.
Foretell {W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Aven Sunstriker

Flying
Double strike (This creature deals both first-strike and regular combat damage.)
Megamorph {4}{W} (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.)

Sublime Archangel

Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
Other creatures you control have exalted. (If a creature has multiple instances of exalted, each triggers separately.)

Imperial Subduer

Whenever a Samurai or Warrior you control attacks alone, tap target creature you don't control.

Guardians of Akrasa

Defender (This creature can't attack.)
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Aven Squire

Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Knight of Glory

Protection from black (This creature can't be blocked, targeted, dealt damage, or enchanted by anything black.)
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Uncaged Fury

Target creature gets +1/+1 and gains double strike until end of turn.

Cathedral of War

This land enters tapped.
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {C}.

Ancestral Katana

Whenever a Samurai or Warrior you control attacks alone, you may pay {1}. When you do, attach this Equipment to it.
Equipped creature gets +2/+1.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Battle Mastery

Enchant creature
Enchanted creature has double strike. (It deals both first-strike and regular combat damage.)

Peerless Samurai

Menace (This creature can't be blocked except by two or more creatures.)
Whenever a Samurai or Warrior you control attacks alone, the next spell you cast this turn costs {1} less to cast.

Asari Captain

Haste
Whenever a Samurai or Warrior you control attacks alone, it gets +1/+0 until end of turn for each Samurai or Warrior you control.

Arashin Foremost

Double strike
Whenever this creature enters or attacks, another target Warrior creature you control gains double strike until end of turn.

Critical Hit

Target creature gains double strike until end of turn.
When you roll a natural 20, return this card from your graveyard to your hand. (A natural 20 is a roll that displays 20 on the die.)

Duelist's Heritage

Whenever one or more creatures attack, you may have target attacking creature gain double strike until end of turn.

Angelic Exaltation

Whenever a creature you control attacks alone, it gets +X/+X until end of turn, where X is the number of creatures you control.

Sigarda's Vanguard

Flash
Flying
Whenever this creature enters or attacks, choose any number of creatures with different powers. Those creatures gain double strike until end of turn.

Akki Ronin

Whenever a Samurai or Warrior you control attacks alone, you may discard a card. If you do, draw a card.

Alpine Watchdog

Vigilance (Attacking doesn't cause this creature to tap.)

Unleash Fury

Double the power of target creature until end of turn.

Sigil of Valor

Whenever equipped creature attacks alone, it gets +1/+1 until end of turn for each other creature you control.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Goblin Champion

Haste
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Phalanx Formation

Strive — This spell costs {1}{W} more to cast for each target beyond the first.
Any number of target creatures each gain double strike until end of turn. (They deal both first-strike and regular combat damage.)

Lizard Blades

Double strike
Equipped creature has double strike.
Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Psychotic Fury

Target multicolored creature gains double strike until end of turn.
Draw a card.

Tempered in Solitude

Whenever a creature you control attacks alone, exile the top card of your library. You may play that card this turn.

Raiyuu, Storm's Edge

First strike
Whenever a Samurai or Warrior you control attacks alone, untap it. If it's the first combat phase of the turn, there is an additional combat phase after this phase.

Double Cleave

Target creature gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Kwende, Pride of Femeref

Double strike
Creatures you control with first strike have double strike.

Assault Strobe

Bloodrage Brawler

When this creature enters, discard a card.

Eiganjo Exemplar

Whenever a Samurai or Warrior you control attacks alone, it gets +1/+1 until end of turn.

Blood Mist

At the beginning of combat on your turn, target creature you control gains double strike until end of turn.

Victory

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Target creature gains double strike until end of turn.

Onward

Target creature gets +X/+0 until end of turn, where X is its power.

Onward // Victory

Fireshrieker

Equipped creature has double strike. (It deals both first-strike and regular combat damage.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Akrasan Squire

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Buccaneer's Bravado

Choose one —
• Target creature gets +1/+1 and gains first strike until end of turn.
• Target Pirate gets +1/+1 and gains double strike until end of turn.

Raking Claws

Target creature gains double strike until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Alpine Houndmaster

When this creature enters, you may search your library for a card named Alpine Watchdog and/or a card named Igneous Cur, reveal them, put them into your hand, then shuffle.
Whenever this creature attacks, it gets +X/+0 until end of turn, where X is the number of other attacking creatures.