Instant Death refers to an attack that immediately kills its victim regardless of what HP they have remaining. Instant death attacks are recurrent throughout the series; several bosses, including final bosses, are known to use instant death moves and some summons, such as Odin and Yojimbo, can also kill instantly.
As with the use of curative and resurrective spells, such as Raise, instant death's effect is often reversed for the undead. In some games, using an instant death ability on the undead will heal it to full in the same way that using Raise would kill it, though there are some exceptions, such as the undead in Final Fantasy XII.
Instant death spells generally do not work on bosses, however, exceptions exist.
Due to the Vanish-Doom Bug, in the versions before the Advance remake the Clear status would remove the target's immunity to instant death, meaning even bosses could be easily defeated this way.
Inflicts extreme non-elemental damage and a chance of Death to all enemies.
Hidden One
Enemy Attack
Inflicts Death.
Joker
Enemy Attack
Inflicts Death. Doesn't always work.
Knife
Enemy Attack
Inflicts Death.
L4 Death
Enemy Attack
Inflicts Death on party whose levels are a multiple of 4.
Scissor Attack
Enemy Attack
Inflicts minor non-elemental damage and Death. Used as a counterattack when HP is 50% or less.
Suffocation Song
Enemy Attack
Inflicts Death. Only used if Gighee is alive, and if at least one opponent has Sadness.
Safety Bit
Accessory
Prevents Death.
Kiss of Death
Item
Inflicts Death on all enemies with 68% precision.
The player can also add the instant death element to a character's physical attacks by linking Destruct Materia with Status Effect Materia in the character's weapon. Equipping the pair in the character's armor will make him/her immune to instant death, instead.
Inflicts Death on all enemies whose levels are a multiple of X. X is broken down into the following:
Crisis Lv 1: LV4 Death
Crisis Lv 2: LV3 Death
Crisis Lv 3: LV2 Death
Crisis Lv 4: LV1 Death
Lv5 Death
Enemy Attack
Inflicts Death on party members whose levels are a multiple of 5.
Rapture
Limit Break
Ejects all targets.
The End
Limit Break
Instantly kills any enemy.
Zantetsuken
Summon
When used by either Odin or Gilgamesh it inflicts instant death to all targets. Odin can use it against the player party if the player runs out of time while battling him.
The player can add the instant death effect to physical attacks by junctioning 100 Death spells to a character's status attack.
Inflicts non-elemental damage and Death. Dark Anima can use it against the party in the International and PAL versions, in which case it inflicts Death regardless of immunity.
Some of user's HP is sacrificed to inflict Instant Death on a foe.
Telega
Boss Skill
Banishes party member.
Kill
Boss Skill
Inflicts Death on vulnerable enemies.
Death Strike
Boss Skill
Inflicts Death on vulnerable party members.
Crushing Fangs
Enemy Skill
Chance of Instant Death.
Prime Level Death
Boss Skill
Instant Death to party members whose levels are a prime number.
Dimensional Rift
Enemy Skill
Chance of Instant Death.
Darkja
Boss Skill
Dark-elemental damage to all party members as well as inflicting Blind and Instant Death. Used by Zodiark.
Death Strike
Boss Skill
Instant Death. Accuracy lowered by target's Shell. Used by Yiazmat.
Warp Mote
Item
Banishes targets.
Deathbringer
Weapon
May cause Instant Death.
Assassin Arrows
Weapon
May cause Instant Death.
All of Yiazmat's physical and rake attacks have 5% of inflicting instant death. In addition, Raise and Arise can cause Instant Death to undead enemies, Raise with 70% success rate, and Arise with 35%.
Assassins can learn the ability Last Breath, which causes instant death, through the weapon Petalchaser. Alchemists can cast the Death spell, which also causes instant death, through the Life Crosier.
Last Breath is an ability which causes instant death and is learned by the Assassin job class. Arcanists can also cause instant death by casting the spell Death.
The player gains access to instant death moves with the Death spell, the Ranger's Smashing Blow (25% chance), Monk's Ghost Army and the Bandit's Deadly Blow attack. The Party Host's Pot Luck command has a random chance of executing Sudden Death that kills all opponents instantly.
Some of the tougher bosses use instant death attacks against the party, such as the Leviathan, that has a chance of instantly KOing a party member with its physical attacks.