History ThatOneAttack / FinalFantasy

* Mega Tonberry is already horrific enough, but pray to the gods if you meet an ''Oversouled'' Mega Tonberry. Its flavor of Karma inflicts HP and MP damage, as well as Stone. If the target has Stoneproof, they are hit with [[TheComputerIsACheatingBastard Confusion that cannot be resisted in any way]]. Hope you don't have any full-heal items in your inventory...

** ''VideoGame/FinalFantasyX'' gives us Great Malboros that uses this as its opening gambit. Wouldn't be a problem if it didn't also get "Ambushed!" ''every single time''. With the characters now poisoned, confused, and blinded, they will now constantly attempt to kill one-another only to miss and take poison damage, which does 1/4th of their maximum HP. This makes poison essentially a 4 turn doom. Frequently you will die without having been given a single chance to do anything. Especially annoying since this actually makes your party ''worse'' as it gets ''better'' - if you have a high Evasion, your only chance to get un-confused - the Greater Malboro's bite - ''keeps missing''.

* Sporefall from Elder Wyrm. Inflicts on the order of 8 status ailments with a large area of effect, probably hitting your entire party unless you really know what you're doing. If you're not prepared, by the time you've recovered from these ailments, it's probably close to casting it again.
** Note that all of the status effects from Sporefall can be cured with upgraded remedies or Esuna, which you do have access to at this point...all of them except Oil, which you're likely to ignore the first time because it doesn't seem to do anything. What does it do? Makes you extremely weak to Fire damage. What's the Elder Wyrm's other favorite attack? Fireball. Boom, KO.
* Disease. It's a debuff that causes the users HP to not be restorable by way of MaximumHPReduction, meaning if you get hit, your HP drops to that and cannot be healed above it again. If a characters gets killed then revived, their left at a single HP. What makes this debuff so frustrating is that the curative item needed to remove it is rare and not available for a long time, and Remedy/Esuna cannot remove it, meaning the only way around it is to return to a save point. If it gets combined with Poison or Sap, it's effectively the same as your character being killed because even if you remove the other debuff, the damage is done, and you'll need to likely bench the unit. The only reliable means of countering it is the Cleanse spell, but it isn't found until during the last chunk of the game, and isn't really placed in an area you can obviously figure out.

* Deathgaze Hollow in Dun Scaith in ''Heavensward'' has one attack that causes a ''huge'' gust of wind to blow you to the side... ''off the stage''. How do you avoid this? You have to either stand in front of the ice crystals that it formed on the ship (Which you tried to avoid less than a second ago) and then you get the warning... unfortunately you are given almost ''no'' time to actually run to one of the two ice crystals. So off you go. Unless you knew to cast Arm's Length or Surecast... which most players, even in TheNewTwenties, ''still'' may have forgotten about (or never bothered using) as almost ''no'' encounters ever ''required'' this before. Or you may simply time it wrong and off you go.

* Construct 7 from the Ridorana Lighthouse raid is notorious for its "Computation Mode," which reduces each player's HP to single digits and requires them to stand in zones that boost their HP to fulfill certain values (divisible by 2, 3, or 5.) Success gives a damage buff, while failure increases damage taken. Not only does the debuff put extra strain on healers, who already have to heal thousands of HP to each player to survive the raid-wide AOE that immediately follows, but beating the DPS check is nearly impossible without a majority of the raid gaining the damage buff. "Computation Mode" returns in the second phase, only this time, it can ask players to turn their HP into ''prime numbers.''

* Hesperos, the fourth raid boss of Pandaemonium, has an attack called Pinax. This attack has several different elemental variants, each with a different but fundamentally simple method of solving them (water creates a big knockback in the center, fire is a big fireball that has to be shared, poison hits everyone at once so players have to be far away from eachother) but one variant in particular is very dangerous: lightning, which will cause a big lightning strike to hit the center of the arena and cause proximity-based damage. On paper this sounds easy enough, just go to the corners of the arena, but what makes it noteworthy is that it's an all-or-nothing attack: if you're outside the range, it will do damage so small it will barely need healing, but if you're even slightly inside the range it's an almost guaranteed death. Pinax also has a delayed effect from when it's cast, and can happen at the same time as other mechanics, which makes it entirely possible for a party to forget about the lightning Pinax or be too late in getting to the corners, causing a full wipe.

* Magnitude 8 from the Hades Gigas/Hill Gigas in Zozo. Does a good chunk of damage to the whole party at a time when you've got one magic healer on your team at best. Also in Zozo, SlamDancer/Veil Dancer's -ra magic, which is enough to oneshot any of your party members, at the time when revival is ''not'' cheap.

* The Brachioraidos' high stats make ''any'' of its attacks this. It starts out with Scorch which not only outspeeds your entire party, but is [[OneHitKill instant death.]] After a bit, it'll begin [[OhCrap counting down from 3.]] Fail to stop the countdown and you'll be hit with a Mega Flare which, if you don't have Reflect on at least one member, is a guaranteed TotalPartyKill.

* Magnitude 8 from the Hades Gigas/Hill Gigas in Zozo. Does a good chunk of damage to the whole party at a time when you've got one magic healer on your team at best.

* Grand Cross, used by Necron and by various other ''Franchise/FinalFantasy'' {{Final Boss}}es.

* Beatrix has Shock, which isn't very nice to take in all the battles against her.

** Later on, another attack will drop meteors onto the platform, with the telegraph being a set of lines and an arrow that points to the area they will hit. Players are supposed to move to safe locations based off where the meteors will land, but not only do the meteors fall from essentially behind the players perspective, but a single meteor hits hard enough to nearly one-shot even tanks. The only saving grace is that in the normal version they have a fixed pattern, not so much on Extreme.

* If the characters' health is particularly high, then normal attacks from enemies that drain health become this, since they follow the same rule [[GameBreaker Blood Sword]] does - each hit deals additional damage equal to 1/16 of target's health. Players who did not level agility and evasion, expecting their HP and defence to carry them are in for a ''rude'' awakening with those guys. Notably, this includes the final boss. It's pretty telling that Starfall X, a move exclusive to the final boss that hits the whole party and seems specifically designed to invoke HolyShitQuotient with its animation, is far easier to deal with than the boss' ''basic attack''.

* Argath has an attack in which you are basically instructed to either do as he says or do the opposite of what you are commanded to do. If it's the Angel face? You comply. If it's the Demon Face? You defy. However, both faces look very similar to one another and the most ''visible'' hint that it's the angel face or the demon face are the colours of the eyes. Unfortunately? It also flashes by ''very'' quickly - so better hope you didn't blink! Or that you're not colourblind.

*

* Disease. It's a debuff that causes the users HP to not be restorable by way of MaximumHPReduction, meaning if you get hit, your HP drops to that and cannot be healed above it again. If a characters gets killed then revived, their left at a single HP. What makes this debuff so frustrating is that the curative item needed to remove it is rare and not available for a long time, and Remedy/Esuna cannot remove it, meaning the only way around it is to return to a save point. If it gets combined with Poison or Sap, it's effectively the same as your character being killed because even if you remove the other debuff, the damage is done, and you'll need to likely bench the unit.

** Note that all of the status effects from Sporefall can be cured with upgraded remedies or Esuna, which you do have access to at this point...all of them except Oil, which you're likely to ignore the first time because it doesn't seem to do anything. What does it do? Makes you extremely weak to Fire damage. What's the Elder Wyrm's other favourite attack? Fireball. Boom, KO.
* And the one for regular enemies is Curse-- this one move can make any enemy into a [[DemonicSpiders demonic spider]]. It works by hitting your party--all of them--with a mana-free (so you can't [[StatusEffects silence]] the enemy or drain its magic), unblockable, unevadeable status bomb that inflicts poison, sap, confusion, and disease--that last one is exceptionally fun, as it means max HP is always equal to current HP, meaning a character cannot be healed while Diseased. Disease needs a special item or spell to remove it, and another spell to remove the other status effects. If a Diseased character dies, rezzing them leaves them with 1 HP and disease, yes, STILL in effect. Because Ribbons are stupidly, horrifyingly rare in this game, you will only be able to protect against ONE of these ailments--if any monsters (plural, ''they come in groups'') who use this attack can be available long before protective armor is. Basically? If three or more of these status effects stay on your party for more than, oh, three seconds? Death. If you are caught without fully upgraded Remedies? Death. No accessories to protect against confusion? Death. [[LuckBasedMission Command priority unkind to you?]] We're so sorry. ''Zodiac Age'' partially remedies this by giving you possibility to steal Ribbons from Trial Mode at your leisure relatively early as well as giving them [[HealingFactor Regen]], but it is still damn annoying.
** Though as bad as that is, there is two small saving graces with that attack: 1) it can only hit each character in succession, even if it affects everyone in an area, and 2) the animation for curse precedes the actually status-inflicting attack. All you really need is one Ribbon, and once the game says the enemy used Curse, wait for the animation to start, [[MenuTimeLockout jump into the inventory screen]] and [[BagOfSharing equip the Ribbon on the character about to get hit.]] Once the Immune message pops up on the character, give the Ribbon to the next victim. Granted, this still relies on finding even one horrifyingly-rare Ribbon, and setting the Gambits so the characters won't die while you watch the animations. Also, it is possible to block Disease with Bubble, meaning having Bubble Rings will make you immune to it.

** Speaking of Ultima, ''any attack that causes Reverse'', though Disease can be just as annoying. Reverse makes you a case of ReviveKillsZombie, while Disease is a NoSell on healing.

* Yiazmat's Reflect and Renew strategy... if not caught, you can heal the boss of all of his HP. all 50,000,000 of it. Its ''basic attack'' also becomes this once its health becomes very low (enough to cast above Reflect on your party). Why? Its attack has 5% chance of an instant kill, in case of combo this chance is per each hit, and on low health it gets combos very frequently up to 12 hits, meaning assuming the damage didn't get the victim before (which is really possible only with Reverse), (s)he still has only about a 54% chance of walking away.

* Vanaspati's final boss has an attack called "Crumbling Sky", which functions similar to the meteors from "The Dark Inside" Trial. Unfortunately, you have to do this while avoiding attacks being thrown at you, and you have to completely get out of the column that the meteor is thrown at you. If you get out by a second before it goes off, you'll still get hit, and which ones are safe can often range from being next to the spot where you are, or ones on the opposite end of the area. The floor also is decorated with visual patterns to try and distinguish it, but for many players it is a ''mess''.

* Vanaspati's final boss has an attack called "Crumbling Sky", which functions similar to the meteors from "The Dark Inside" Trial. Unfortunately, you have to do this while avoiding attacks being thrown at you, and you have to completely get out of the column that the meteor is thrown at you. If you get out by a second before it goes off, you'll still get hit, and which ones are safe can often range from being next to the spot, or ones ont he opposite end of the area.

* If the characters' health is particularly high, then normal attacks from enemies that drain health become this, since they follow the same rule [[GameBreaker Blood Sword]] does - each hit deals additional damage equal to 1/16 of target's health. Players who did not level agility and evasion, expecting their HP and defence to carry them are in for a ''rude'' awakening with those guys.

* That boss in particular? Mustadio. Who sports two of these:
** Left Handgonne and Right Handgonne. Just like with Alphascape v3.0 Omega, you have to know to avoid ''his'' right and ''his'' left. This isn't bad enough as he gives a little more of a warning than Omega. The downside is that in the later phases, he brings otu adds that will force the raid (including the tank) to scatter right and left... and will ''still'' use the Handgonnes, which means that if he's facing ''you'' or the tank had to go to the other side to avoid getting a Vulnerability Up stack? You have no way to escape.
** Analysis has Mustadio analyze all your weaknesses, and in doing so he summons 3/4 of a circle around you - 1/4th of your body is blank. Mustadio's taunts is that he's analysed your weaknesses - making it seem as if he is talking to the group. Oh no, he's actually talking to ''you'' - and you have to point the area that's ''not'' covered by a circle piece ''towards'' where ''he'' is - which isn't intuitive and resulted in many memes about "Hole to Mustadio" or sprouts all falling at once comparing it to ''Series/SquidGame''. Coupled with this is [[ScrappyMechanic very few people think to explain this]], like ''any'' mechanic.

** One which will summon areas you should avoid and have been trained to avoid since ''A Realm Reborn''. However? ''Now'' the boss will ''rotate'' the stage. Thought you were safe? Well now you're getting a stack of Vulnerability up. You can't adjust yourself until after the platform is rotated.
** Later on, another attack will drop things from the sky... all while you're trying to know where to go. By the time the player is successfully out of the way? Another star is falling. You can find out where they are by [[ViolationOfCommonSense looking up at the sky]]... except if you do that you can't see the ground.
* Vanaspati has a few particularly annoying attacks in the final boss:
** One will use patterns to tell you where the attack will go. Unfortunately? It's a ''mess'' of patterns. It's a simple "Go to the opposite colour". Which is [[SarcasmMode very helpful if you're colour blind]]. Fortunately, [[AntiFrustrationFeatures the colours are associated with a pattern which will appear on your screen]]. Hopefully you don't blink - and [[GuideDangIt know that the pattern is the OPPOSITE of where you should go]].
** "Crumbling Sky" will, much like "The Dark Inside", drop projectiles from above. Unfortunately, you have to do this while avoiding ''other areas'' - meaning if you have ''any'' lag or even [[HitboxDissonance have a single pixel of yourself in the zone]]? You get hit.

* Alphascape V3.0 Omega has one attack that the community ''hates'' with a passion; Star/Larboard Wave Cannon. The attack is a cone like AOE that attacks either Omega's right, or left side, while placing a Vulnerability Up debuff on any player hit. The main issue players have is simply the name -- not everyone immediately recognizes the nautical terms "starboard" (right side) and "larboard" (left side). Even those who do have difficulty figuring out quickly because the terms are so similar -- real-world sailors long ago retired the term "larboard" in favor of "port" for ''exactly this reason''. Making this worse is that Omega immediately rotates 180 degrees and follows it up with a second one -- and since "Starboard" and "Larboard" are from ''his'' perspective, you have to quickly figure out whether to stay put or move to the other side to dodge the next one. This attack alone is considered the reason the fight is hard, as nothing else in the fight is as difficult to figure out as that. The developers seemed to realize this and worked to give the attacks more understandable names, such as the first boss of the Orbonne Monastery having a similar move that is easily identifiably by the name.

** "T.G Holy Sword" takes ConfusionFu to a new degree. The attack is actually one of three moves, but they all share the same name, the way to tell what to do involves his animations. If he plants his swords down and leans in, you need to run into the platform to dodge the attack. If his swords point to a platform, each of the platforms he points out will be struck, meaning you need to run to a different one. If he stabs into the platform, you need to run to the pact to avoid it. All this the player has to remember from watching his animations, something new players heavily struggle with.

* Any ''Franchise/FinalFantasy'' game with 10[[superscript:x]] Needles, where x>=4. OneHitKO that can't be blocked.

* Grand Cross is usually used by the final enemy of a game and it inflicts even more status conditions (sometimes some that can't be defended against) than Bad Breath. What makes it worse is that it inflicts at the same time conditions alongside death such as Zombie that makes it so revive spells and Phoenix Downs can't revive the downed character as they are zombied.

* Big Bang from Zeromus. Deals lots of damage, and any survivors suffer continual hit point loss. The BonusBoss version of Zeromus in the GBA version, Zeromus EG, can do this move two times in a row.

* Encircle, from pretty much any enemy that uses it (thankfully, not many of them). It erases a character from the battle, which means they're effectively dead, and it's impossible to reverse the effects of it once it's been cast (except by ending the battle). The only way to stop it is with the Aegis Shield, which only has a 1 in 3 chance of actually succeeding, and only on the character targeted by the attack; it's very unlikely you'll have four Aegis Shields. Oh, and one of the enemies with access to this move is [[BonusBoss Omega]].

* [[BonusBoss Shinryu]]'s [[MakingASplash Tidal Wave]], which he always uses [[BeginWithAFinisher at the start of battle]]. Didn't bring Water protection or a way to Berserk him? Enjoy [[TheresNoKillLikeOverkill around 8000 damage to everyone]]. It left so big an impact on players, this attack reappeared in pretty much ''every'' game where Shinryu is, and he (almost) always opens the battle with it.

* There's also BonusBoss Emerald Weapon's Aire Tam Storm, which deals 1,111 damage per materia equipped on the target party member. Since [[GuideDangIt nobody mentions this little detail]] it almost always does maximum damage, and since it targets everyone, well... You'd better have Phoenix and Final Attack equipped. And if you know the [[SdrawkcabName trick]], it becomes trivial to take out half of its hit points in retaliation. Still a GuideDangIt on the first play through, but one you can use to your advantage.
* BonusBoss Ruby Weapon also has quite an annoying ThatOneAttack in Whirlsand, which removes one character from battle, basically making them permanently dead for the rest of the battle. He can use this attack ''two times'' in a row if you're not prepared. [[GuideDangIt You have to wait until Ruby Weapon buries its claws in the sand,]] and start the battle with two members dead to dodge Whirlsand. Still, not an ideal start one would like for the battle. Not to mention that if you try to use Knights of the Round on it, it'll retaliate with Ultima.

* The [[BonusBoss bonus bosses]] have some annoying attacks. First is Light Pillar, which instantly kills one party member with 9999 damage. This isn't too bad, you can fix that quickly enough with a Phoenix Down or the Revive command. They also have Gravija, which deals percentage-based damage. Can't kill you, but makes it easier to die unless you heal fast. There's also an attack called Megiddo Flame which does 9998 damage. The game assumes that by the time you're facing a BonusBoss, you're good enough to have 9999 HP and a repertoire of healing spells, which is pretty much the only way to survive that attack. But the worst of them all is Omega Weapon's Terra Break. It is a more powerful clone of the Meteor spell, which randomly divides ten attacks across your party. Now, Meteor isn't too bad, if you're lucky, it'll hit someone with lots of HP or spread the damage out evenly enough that your party survive, and the ten hits don't do much damage anyway. But Terra Break is not like that. Terra Break is like a physical-attack version of Meteor, except each hit does upwards of 3000 damage, damage which is not mitigated by your Vitality stat like most physical damage is. Even if your entire party has 9999 HP at the time, without proper preparation, it is nearly impossible to survive. Your only options are to make your party invincible with items, or had everyone summon their [=GFs=] beforehand to absorb the damage. You can also cast Protect on the entire party to halve the damage of each hit, but that won't ensure that your whole party remains standing. Alternatively, assuming you have [=GFs=] that still know the [[NotCompletelyUseless otherwise useless]] Defend command, you can order your party to Defend against the attack, which will nullify the damage completely. And even then, you have to know where Terra Break comes up in Omega Weapon's attack sequence. The easiest way to 'deal' with Terra Break is just to kill Omega before he uses it, which isn't actually all that hard if you're well-junctioned and spam [[LimitBreak Limit Breaks]].

* Also in VIII, Ultimecia's Hell's Judgement spell that will put the entire party's HP down to one and she will use this often. Interestingly, this otherwise devastating attack can make the final battle a cinch, giving the whole party (or what's left of it) an opportunity to spam [[DesperationAttack Limit Breaks]]. If ever there was a time to use the [[NighInvulnerability total-party-invincibility-granting Holy Wars]] that [[TooAwesomeToUse you've been hoarding]], [[GameBreaker this would be it]].
** Ultimecia's unnamed Time Compression related move that completely deletes one of your Magic Stockpiles at random. This can instantly render one of your characters completely helpess or useless.

* The magic spell Curse from the same game also has the same effect while adding in significant damage. [[BonusBoss Bonus Bosses]] Hades and Ozma use this spell (without warning in Ozma's case).

* Dark Yojimbo's Zanmato overdrive, unfortunately for you, works exactly the same as its playable version (An instant party-wide OneHitKill, impossible to resist in any way). Did you have another Aeon out? You live this time. Did you ''not'' have a summon out? Congratulations, your party's dead, and your Auto-Life crumbles like a biscuit hit with a hammer.

* The [[BonusBoss Shinryu's]] ''Eraser'' attack that instantly petrifies a character and, like ''Fangs of Hell'', [[TheComputerIsACheatingBastard punches through any status immunity the target has]]. This wouldn't be too bad, but this fight takes place underwater, meaning the petrified character [[LiterallyShatteredLives instantly shatters]] and cannot be replaced for the rest of battle, and the attack [[AlwaysAccurateAttack cannot be dodged]]. The only saving grace is the fact Shinryu stops using it once there is only one party member left.
** Speaking of petrified, it can be a dangerous move to, as any enemy can be able to use a physical attack against the petrified character, like Seymour's Shattering Claw, and the character would instantly shatter. To prevent this, The petrified character would have to be un-petrified with Soft or Remedy.
* Nemesis, the final BonusBoss of the Monster Arena, has an attack that is aptly named [[NamesToRunAwayFromReallyFast Armageddon]]. It's a straight-up TotalPartyKill that is unblockable, unavoidable, and not telegraphed in any way. In order to defeat Nemesis, you will '''need''' Auto-Life, as otherwise Nemesis can just cause an instant GameOver in one attack with nothing you can do about it. While it is also possible to sacrifice an aeon to protect yourself from it, you will need to know that it's coming - either being very lucky or memorizing Nemesis' exact attack sequence. Funnily enough its weakest attack that could be mitigated is Ultima, the strongest black magic in the game. Even its standard physical attack does more very high damage.
* Penance, [[RegionalBonus International/PAL's]] version BonusBoss has [[NamesToRunAwayFromReallyFast Judgment Day]]. It is performed only when both of its arms are alive, is guaranteed to kill the whole party and should you have Auto-Life, the arms will finish you off. The main point of this fight is to ''prevent'' this attack.

* Dark Magus Sister's Delta Attack is at it again. It is a party-wide HPToOne and ManaBurn (to zero, mind you) rolled in one package. Hope you have an Alchemist ready to use some recovery items, otherwise you might be screwed.
** Likewise, Dark Yojimbo's Zanmato. Pretty much the same deal as above, except it generously leaves you with ''one'' MP.
** Mushroom Cloud and Pernicious Powder. Pretty much Marboro's Bad Breath, it also lowers the stats of a party to one sixth if it doesn't kill you outright. Not good considering [[DemonicSpiders what enemies]] it appears with.
** Anything that inflicts Confusion in this game. ''X-2''[='=]s flavor of Confusion not only causes the victim to attack allies, but just straight up use attacks, skills, and items indiscriminately. Like, for example, use a Megalixir on ThatOneBoss that you were one hit away from defeating.

** And the one for regular enemies is Curse-- this one move can make any enemy into a [[DemonicSpiders demonic spider]]. It works by hitting your party--all of them--with a mana-free (so you can't [[StatusEffects silence]] the enemy or drain its magic), unblockable, unevadeable status bomb that inflicts poison, sap, confusion, and disease--that last one is exceptionally fun, as it means max HP is always equal to current HP, meaning a character cannot be healed while Diseased. Disease needs a special item or spell to remove it, and another spell to remove the other status effects. If a Diseased character dies, rezzing them leaves them with 1 HP and disease, yes, STILL in effect. Because Ribbons are stupidly, horrifyingly rare in this game, you will only be able to protect against ONE of these ailments--if any monsters (plural, ''they come in groups'') who use this attack can be available long before protective armor is. Basically? If three or more of these status effects stay on your party for more than, oh, three seconds? Death. If you are caught without fully upgraded Remedies? Death. No accessories to protect against confusion? Death. [[LuckBasedMission Command priority unkind to you?]] We're so sorry. ''Zodiac Age'' partially remedies this by giving you possibility to steal Ribbons from Trial Mode at your leisure relatively early as well as giving them [[HealingFactor Regen]], but it is still damn annoying.
*** Though as bad as that is, there is two small saving graces with that attack: 1)it can only hit each character in succession, even if it affects everyone in an area, and 2) the animation for curse precedes the actually status-inflicting attack. All you really need is one Ribbon, and once the game says the enemy used Curse, wait for the animation to start, [[MenuTimeLockout jump into the inventory screen]] and [[BagOfSharing equip the Ribbon on the character about to get hit.]] Once the Immune message pops up on the character, give the Ribbon to the next victim. Granted, this still relies on finding even one horrifyingly-rare Ribbon, and setting the Gambits so the characters won't die while you watch the animations. Also, it is possible to block Disease with Bubble, meaning having Bubble Rings will make you immune to it.
** The FinalBoss has Flare attacks. Mega Flare isn't too bad, but Giga Flare Sword can be nasty and Tera Flare is even worse]]. For the record, the latter deals 4000+ damage to everyone, in a game where the maximum is, without Bubble, around 6500. Worse yet, you can't prevent it because the boss will use ''both'' Palings before pulling this off. Hope you didn't neglect your secondary members too much otherwise this attack alone can finish you off.
** Growing Threat is used by some bosses to double their level, and thus their damage output.
** Zalera's Kill. [[{{ExactlyWhatItSaysOnTheTin}} Three guesses on what it does]]. Spammed often if you don't understand how the battle is to be fought. In addition to Kill, Zalera seems to be the math instructor from hell. Any spell he has is a level based disabler of some sort, and his ultimate attack is a group wide instant death spell. Don't worry, it won't kill you if your level isn't a prime number... which is the easiest way to not get hit by all of his other level-based spells. You can beat Zalera by just knowing not to be a prime ''or'' a multiple of 3, 4, or 5.
** Divide, which is used by some ghost enemies such as Necrophobe. Enjoying a fight against Death and Doom-spamming ghost that likes to teleport out of your range? Hope you like fighting one more!
** Zodiark's Darkja, which blinds and does an instant kill. You can absorb the dark damage, block the blind status, but you will have nadda for the instant kill effect. Luck will almost never be on your side after it is cast.
** Chaos's Aeroja. It deals wind damage and confuses. Not so bad since your allies will snap out of it with a bonk to the head right? Normally so; except in Chaos's battle, you can't use physical attacks at all. So you can't snap yourself out of confusion if all three allies are confused in the fight.
** Ultima's Holyja. It deals holy damage and causes Reverse. Ultima then casts Renew on your team shortly after Holyja (no charge time required) causing an instant kill. If Reflect is on your team when it happens...
*** Speaking of Ultima, ''any attack that causes Reverse'', though Disease can be just as annoying. Reverse makes you a case of ReviveKillsZombie, while Disease is a NoSell on healing.
** Yiazmat's Reflect and Renew strategy... if not caught, you can heal the boss of all of his HP. all 50,000,000 of it.
** Yiazmat's ''basic attack'' becomes this once its health becomes very low (enough to cast above Reflect on your party). Why? Its attack has 5% chance of an instant kill, in case of combo this chance is per each hit, and on low health it gets combos very frequently up to 12 hits, meaning assuming the damage didn't get the victim before (which is really possible only with Reverse), (s)he still has only about a 54% chance of walking away.
** Any sort of barrier or paling that a boss may put up on itself. An impregnable defense that only goes down over the course of time? Enjoy your unnecessarily long boss fight.
** By the end of the game pretty much any enemy that can cause confusion will be extremely dangerous. Your party members will be strong enough to effortlessly one-shot each other with physical attacks, so a single confused ally can wipe out the rest of the party in just two turns. In theory this should be more than enough time to cure thim - except that the command priority always gives a huge advantage to physical attacks. Even if you see an enemy casting confusion on a character and immediately tell ''both'' of the other two to throw him a curative item there is still a good chance that he will wipe them both out before they can perform the action.
*** This can be mitigated by the fact the game allows you to switch equipment of your team at any time, even in the middle of combat, so you can switch weapon of confused character to something much weaker. In fact, there is an entire class of weapons called Measures, which seem to serve no other purpose than to hit other party members with them, as they deal little damage and grant positive status buffs upon target.
** Time Requiem is a monster-exclusive spell that inflicts Stop over a wide area. Hope your party members weren't too close together, or else you're going to be there for a while.

* Dies Irae. The first form of Orphan tends to use this move when you're close to defeating it. It can be an instant Game Over if your party leader doesn't have full health.
** Speaking of Orphan, he's also got Progenitorial Wrath, a OneHitKill attack that he targets your leader with, in a game with WeCannotGoOnWithoutYou (even if your [=AI=] Medic is ready with a Revive), and Death resistance items that can never give 100% immunity to it. FakeDifficulty, ho!

* Orphan's second form's Temporal Hollow. Doesn't do much, dispels a few buffs and debuffs, and resets the boss' stagger meter...except said boss can't be damaged except when it's staggered...and its AI is set to use Temporal Hollow when you approach stagger...and you're on a strict time limit for this fight.

* The average player of this game can get traumatic flashbacks from just three words: "Counter Any Ability". To elaborate, while ''all'' of the myriad counters newly added to this game are [[ScrappyMechanic various degrees of annoying]], this one is likely the [[TheComputerIsACheatingBastard worst and cheapest]] of the whole bunch. It's not an ''attack'' per se; what it does is, whenever you use ''any'' job skill, the boss can get additional BP for free, which they will merrily use for whatever nasty attack or combo they feel like. The only limitation to this is the maximum BP stock of 3; there is no limit to how frequently or how many times they can do it, nor is there a way to turn it off (unless you can inflict [[StatusEffects Dread]] on them). Have fun when the boss you're fighting [[RandomNumberGod randomly]] takes three [[ExtraTurn extra turns]] because you decided to heal or buff multiple characters. Late in the game, you can even face ''multiple'' enemies that can all counter simultaneously, giving the enemy party three or four extra actions for your one. (Granted, those are [[BonusBoss optional fights]], but the Infinity+1 job skills are locked behind them, and if the developers wanted to discourage GameBreaker strategies, this ''probably'' wasn't the way to do it....)

* Dark Yojimbo's Zanmato overdrive. Did you have a summon out? You live this time. Did you ''not'' have a summon out? Congratulations, your party's dead, and your Auto-Life crumbles like a biscuit hit with a hammer.
* Dark Magus Sisters' overdrive, Delta Attack, deserves a mention too. It deals six hits of higher Damage {{Cap}} and like Dark Yojimbo's Zanmato it removes Auto-Life. While it can be performed only when all three sisters are fought together, are alive and have their overdrive bars fully charged, if you're unable to run away farther from them during minigame they'll get an ambush on your party with them being ready to perform it.

* Alphascape V3.0 Omega has one attack that the community ''hates'' with a passion; Star/Larboard Wave Cannon. The attack is a cone like AOE that attacks either Omega's right, or left side, while placing a Vulnerability Up debuff on any player hit. The main issue players have is simply the name -- not everyone immediately recognizes the nautical terms "starboard" and "larboard". Even those who do have difficulty figuring out quickly because the terms are so similar -- real-world sailors long ago retired the term "larboard" in favor of "port" for ''exactly this reason''. Making this worse is that Omega immediately rotates 180 degrees and follows it up with a second one -- and since "Starboard" and "Larboard" are from ''his'' perspective, you have to quickly figure out whether to stay put or move to the other side to dodge the next one. This attack alone is considered the reason the fight is hard, as nothing else in the fight is as difficult to figure out as that. The developers seemed to realize this and worked to give the attacks more understandable names, such as the first boss of the Orbonne Monastery having a similar move that is easily identifiably by the name.

* From the ''Eden Savage'' raid, specifically Shiva, we have one of the most dreaded mechanic that ever graced the game: Light Rampant. Everyone is afflicted with a debuff that, if it crosses a certain threshold, will make one player's character explode and kill everyone with them. To avoid this, the party must execute the following mechanics perfectly. Said mechanics involve baiting attacks, stand in towers that require a specific number of players, move between the new towers that appear afterwards, all the while with the players being tethered to eachother (and breaking the tethers, by standing too close or too far from your tethered partner, spells an immediate total party wipe - since the tethered persons can change between each try, players need to assign positions and potentially move to adjust), and bait 4 orbs of lights that are also tethered to players and pursue them. Players with orbs must bait them long enough for them to shrink and then willingly make them explode by running into them, but they also have to make sure to not get hit by Shiva's conal attacks (baited by other players and based on their proximity to Shiva, meaning that the players with the orbs must position themselves carefully to avoid baiting the attack themselves) and that the orbs don't explode near other players, lest their debuff would hit the threeshold and wipe their team. The whole mechanic leaves absolutely no room for error, as a single mistep by any player will inevitably kill everyone. Dozens of different strategies have been made to deal with it, and even the most popular ones are still hard to execute. This is the mechanic that broke many static teams, and that newcomers and veterans alike dread.

* Elidibus [[spoiler:as the Warrior Of Light]] has Ultimate Crossover, which will ''instantly'' kill the entire party and has no way to be dodged. The only way to avoid it is for a Tank to use a Level 3 LimitBreak. It should be noted that ''no'' other regular, non-Extreme Trial boss ever required a Tank's Level 3 LB to survive before him, so there's no real way to prepare for it other than to know this beforehand. Doubles also as a KaizoTrap, as he only uses it after his first phase is over. Die, and you have to start from phase 1 all over again, survive and a checkpoint will be made after the attack. And while the only other boss to do this, Alexander Prime, had a convenient tell when to cast the Limit Break, Elidibus does not. It's "sometime after his limit break bar fills up"

* Elidibus [[spoiler:as the Warrior Of Light]] has Radiant Meteor, an attack that puts an incredibly large AOE circle on four random players and then drops a meteor on them. Of all his attacks, its widely seen as the most frustrating one to handle, because its random who he will pick, but also very difficult to space every target from each other due to how wide the area is, and how random it can be. Very few times will a player be able to leave a good open spot for the rest of the party to go to because of this, meaning it is easy to almost wipe just from bad positioning and luck.