Spirit Sword is a passive item.
- Replaces Isaac's tears with a sword he can swing in front of him.
- The sword swing can collect pickups.
- Holding an attack button charges a spin attack, ready when the sword flashes, which damages all enemies around Isaac, more than a normal sword slash does.
- The spin attack can destroy projectiles and shopkeepers.
- Note: Unlike most charge attacks, you can't charge in the direction of the attack by pressing and holding a different attack button then releasing the old one. Instead, it will stay pointing the same direction until all attack buttons are released, either doing nothing or using the spin attack, or the sword touches and damages an enemy, dealing sword slash damage.
- The sword fires a projectile when swung.
- Only one projectile can be active at once.
- The sword has 2 projectiles, one that is fired when the spin attack is done, which is faster and has higher damage, and one that is fired when it is swung normally, which does not fire unless Isaac is at full health.
- Anti-Gravity: Sword projectiles will stay still for a short time
- Blood Clot: Every other swing is a red sword, dealing extra damage.
- Brimstone: Spin attack releases Brimstone.
- Spirit Sword won't allow the player to change the face direction without releasing the charge, making it harder to aim, especially with quick/teleporting enemies around the room.
- Cricket's Body: Sword projectiles will split upon falling to the ground
- Dr. Fetus: Overrides Dr. Fetus.
- Epic Fetus: Overrides Epic Fetus.
- Eye Sore: Adds swords around Isaac which also swing.
- Eye Of The Occult: When at full health, fires a controllable sword projectile that lasts for a few seconds until it hits something or falls to the ground. This effect allows multiple sword projectiles to exist onscreen simultaneously.
- Godhead: Sword projectiles have the Godhead's aura
- Ipecac: Sword causes poison damage, all beams explode as Ipecac would. Your damage stat is not affected by +40 damage from Ipecac.
- Loki's Horns: Chance to swing 4 swords around Isaac.
- Lost Contact: Sword swings deflect projectiles.
- The Ludovico Technique: Overrides The Ludovico Technique.
- Menorah: Both spins and projectiles launched are multiplied.
- Mom's Knife: Spin attack throws the sword and causes it to spin several times before returning to Isaac. Spirit Sword will open the door to Corpse as long as you have Mom's Knife.
- Monstro's Lung: A fully charged spin attack fires a large, 360° wave of tears.
- The Inner Eye: Adds 2 additional spins to fully charged attack and 2 more projectiles.
- Mutant Spider: Spin attack spins 3 more times, and fires 3 more projectiles.
- Oculus Rift: The sword can summon rifts whenever it hits enemies or its projectiles hit an enemy or obstacle.
- Tammy's Head: When used, spins multiple swords around Isaac before firing Sword projectiles in 8 directions.
- Technology: Changes the appearance of the sword to resemble a lightsaber. Slight range increase on fully charged spin attack. It also causes enemies around the lightsaber to suffer constant damage.
- Tiny Planet: Sword projectiles orbit around Isaac.
- Blindfold: The Spirit Sword does not work if you are blindfolded.
- Spoon Bender: Sword projectiles will home on enemies and make the sword purple
- Death's Touch: Sword projectiles penetrate through multiple entities.
- Spirit Sword's functions are inspired by how Link's swords work in the Legend of Zelda series, particularly the post-NES 2D games. The name, description, and item pool of Spirit Sword means that it is likely a Master Sword epoxy. The beam firing is only a feature of the upgraded swords in those games.
- The name Spirit Sword is a reference to the Sword of the Spirit, one of the many armaments that make up the Armor of God. This is further supported by the fact that it is an Angel Deal item.