Isshin, Two Heavens as One

If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Fateful Absence

Destroy target creature or planeswalker. Its controller investigates. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Selfless Samurai

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

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.

Reinforced Ronin

Haste
At the beginning of your end step, return Reinforced Ronin to its owner's hand.
Channel — {1}{R}, Discard Reinforced Ronin: Draw a card.

Secluded Courtyard

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

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.

Intercessor's Arrest

Enchant permanent
Enchanted permanent can't attack, block, or crew Vehicles. Its activated abilities can't be activated unless they're mana abilities.

Ecologist's Terrarium

When Ecologist's Terrarium enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{2}, {T}, Sacrifice Ecologist's Terrarium: Put a +1/+1 counter on target creature. Activate only as a sorcery.

Clifftop Retreat

Clifftop Retreat enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Plains

Imperial Subduer

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

Tempered in Solitude

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

Mountain

Pillarverge Pathway

Needleverge Pathway

Needleverge Pathway // Pillarverge Pathway

Environmental Sciences

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Rabbit Battery

Haste
Equipped creature gets +1/+1 and has haste.
Reconfigure {R} ({R}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

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.

Kindled Fury

Target creature gets +1/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.