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

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.

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

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.

Wind-Scarred Crag enters the battlefield tapped. When Wind-Scarred Crag enters the battlefield, you gain 1 life. {T}: Add {R} or {W}.

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.)

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.)

Destroy target creature that was dealt damage this turn. Draw a card.