Killer abilities affect a certain monster type, causing massive damage to enemies of that type. These abilities have been around since the original Final Fantasy, though in the original and PS releases, it was bugged and did nothing. They are normally found on weapons.
The following abilities appear in the game:
- Ogre Killer - Ogrekiller
- Undead Killer - Light Axe, Sun Blade
- Dragon Killer - Wyrmkiller
- Mage Killer - Rune Blade
- Wolf Killer - Werebuster
- Aquatic Killer - Coral Sword
- Giant Killer - Great Sword
- Ogre Killer - Ogrekiller
- Mage Killer - Rune Axe
- Were Killer - Werebuster
- Divider Killer - All Katanas
- Dragon Killer - Wyvern Lance, Artemis Arrow, Dragon Whisker, Dragon Claws, Apollo's Harp, and Loki's Lute.
- Machine Killer - Lightning Arrow, Wooden Hammer, Mythril Hammer, Gaia Hammer, Thor's Hammer, Flare Sledgehammer, and Loki's Lute.
- Beast Killer - Ice Rod and Loki's Lute.
- Ghoul Killer - Ancient Sword, Mythril Sword, Holy Lance, Holy Arrow, Mythril Hammer, Mythril Staff, Loki's Lute, Lightbringer, Coral Sword, and Mythril Knife.
- Giant Killer - Blood Sword, Blood Lance, Ogrekiller, Angel Arrow, Perseus Arrow, Faerie Claws, Loki's Lute, and Poison Axe.
- Flan Killer - Index Finger, Blood Sword, Blood Lance
- Mage Killer - Rune Axe, Elven Bow, Silencing Arrow, Mage Masher, Rune Staff, and Loki's Lute.
- Undead Killer - Ragnarok, Blood Sword, Blood Lance, Holy Arrow, Godhand, Sage's Staff, Loki's Lute, Lilith Rod, Mythril Staff, and Lightbringer.
- Dragon Killer - Artemis Arrow.
- Machine Killer - Lightning Arrow, Mythril Hammer, and Gaia Hammer.
- Ghoul Killer - Mythril Sword, Holy Arrow, Mythril Knife, and Mythril Hammer.
- Giant Killer - Faerie Claws.
- Flan Killer - Index Finger.
- Mage Killer - Rune Staff.
- Undead Killer - Holy Arrow, Lilith Rod, and Mythril Staff.
- Dragon Killer - Dragon Claws, Apollo's Harp, Loki's Harp, Wyvern Lance, and Dragon Whisker.
- Machine Killer - Lightning Arrow, Lightning Claws, Phase Cutter, Hammer, Wooden Hammer, Mythril Hammer, Gaia Hammer, Loki's HarpSledgehammer, Thor's Hammer, and Loki's Harp.
- Demon Killer - Muse Harp, Loki's Harp, and Demon Slayer.
- Ghoul Killer - Holy Arrow, Mythril Knife, Mythril Hammer, Silver Harp, Muse Harp, Loki's Harp, and Mythril Sword.
- Giant Killer - Ogrekiller, Angel Arrow, Perseus Arrow, Phase Cutter, and Loki's Harp.
- Flan Killer - Loki's Harp.
- Mage Killer - Rune Axe, Silencing Arrow, Mage Masher, and Loki's Harp.
- Undead Killer - Holy Arrow, Muse Harp, and Loki's Harp.
- Giant Killer - Cleaver
- Aevis Killer - Aevis Killer
- Magic Beast Killer - Artemis' Bow
- Dragon Killer - Dragon Lance
The only Killer ability in the game is the Man-Eater, which deals double damage against human targets.
Zidane, Steiner, Freya and Amarant can equip various Killer abilities that make physical attacks deal 1.5x damage to the corresponding enemy type. Killer abilities do not stack in case an opponent belongs to more than one category. For example, Dracozombie is both an undead and a dragon, but it gives no additional benefit to equip both Killer abilities; as long as either Undead Killer or Dragon Killer is equipped the attacker will deal maximum damage.
- Man Eater - Human types
- Dragon Killer - Dragon types (Freya only)
- Bird Killer - Flying types
- Devil Killer - Demon types
- Beast Killer - Beast types
- Bug Killer - Bug types
- Stone Killer - Stone types
- Undead Killer - Undead types
Gun Mage's Fiend Hunter abilities do 4x damage to monsters of a specific type.
The following is a list of abilities found in the Fiend Hunter skill:
- Shell Cracker - 4x damage to "Helm" types.
- Anti-Aircraft - 4x damage to "Birds" and "Wasps" types.
- Silver Bullet - 4x damage to "Lupine" types.
- Flan Eater - 4x damage to "Flan" types.
- Elementillery - 4x damage to "Element" types.
- Killasaurus - 4x damage to "Reptile" types.
- Drake Eater - 4x damage to "Drake" types.
- Dismantle - 4x damage to "Machina" types.
- Mech Destroyer - 4x damage to "Mech" types.
- Demon Muzzle - 4x damage to "Imp" and "Evil Eye" types.
Killer abilities cause increased damage and gives a chance to intimidate the creature. This effect is similar to Paralysis. Most creatures possess an appropriate killer effect versus creatures in an opposing ecosystem. Some ecosystems, such as beastmen and elementals, are exempt from this, due to their nature of opposing their enemy in the ecosystem rather than simply being eaten by them like ordinary ecosystems.
- Beastmasters gain multiple Killer abilities, similar to wildlife.
- Blue Mages have access to multiple Killer abilities through Blue Magic Synergy.
- Dark Knights have Arcana Killer.
- Dragoons have Dragon Killer.
- Samurai have Demon Killer.
- Paladins have Undead Killer.
- Some equipment may grant other Jobs these effects.
- Conversely, the Crimson Mail/Blood Mail gives players "dragon affinity" when worn, which has a downside of making them intimidated by anything with Dragon Killer.
- Spirit Killer - Ogre.
- Insect Killer - Coral.
- Humanoid Killer - Muramas.
- Reptile Killer - Dragon.
- Undead Killer - Sun.
The "Slayer" abilities used by Rangers deals 1.5x the damage of a conventional attack to various enemy types.
The following is a list of them:
- Bug Slayer - Bug family
- Plant Slayer - Plant family
- Beast Slayer - Beast family
- Aerial Slayer - Aerial family
- Aquatic Slayer - Aquatic family
- Dragon Slayer - Dragon family
- Undead Slayer - Undead family
- Demon Slayer - Demon family
- Humanoid Killer - Man-Eater, Duel Sword, Kunai, Asura, Osafune, Kotetsu, Kikuichimonji, Sasuke's Blade, Murasame, Masamune, Ame no Murakumo, Mutsunokami, Muramasa, Ogrekiller, Giant Axe, Godhand
- Undead Killer - Wightslayer, Lightbringer, Excalibur, Masamune, Ame no Murakumo, and Staff of Light.
- Dragon Killer - Durandal, Mutsunokami, Heavy Lance, Wyvern Lance, and Dragon Claws.
- Demon Killer - Lustrous Sword, Osafune, Godhand, Silver Bow, and Sagittarius Bow.
- Animal Killer - Kotetsu and Tiger Fangs.
- Plant Killer - Kikuichimonji, Battleaxe, Slasher, Mythril Axe, Dwarven Axe, Death Sickle, Greataxe, Ogrekiller, Rune Axe, Sledgehammer, Crystal Axe, Giant Axe, and Sagittarius Bow.
- Machine Killer - Sasuke's Blade, Murasame, War Hammer, Shock Hammer, Gaia Hammer, Demon Axe, Thor's Hammer, Earthbreaker, and Rocket Punch.
- Ghost Killer - Rune Axe.