History ThatOneBoss / FinalFantasyRecordKeeper

** The ''XI'' realm version of Bahamut is regarded as the hardest of them all for many reasons. He's considered to be among the tankiest by stats alone and having more HP on average and he's one of the three Bahamut fights with Dispel (the other two being ''V'' and ''Tactics''). Putting together a proper team is difficult since ''XI'' banners are rare, Aphmau is considered of the lower-tier White Mages in the game, and the realm doesn't have good synergy; a full mage team isn't possible since Shantotto and Arciela are the only mages of the realm, and physical teams don't have a reliable way to boost their critical hit rate and damage. Needless to say this one tends to be the last one completed by many expert players.

** Calcabrina for ''FFIV'' hits hard with both physical and magical attacks across Water, Earth, Fire, and Dark elements, and most of its attacks are group-hitting. However, it's the gimmick-y attacks you need to be careful of. It can use Ultimate Hold on your middle party member to Paralyze them on its second turn, and in its third and fourth phases it'll use Ultimate Hold on your ''three'' middle party members; since the ''IV'' realm has no one with Esunaga or Astra on their Soul Break, you either need to do enough damage to push it to its next phase before it can use Hold (very difficult since it is always used on the second turn of each phase), a Magicite effect, or a Blink effect to avoid Hold entirely. In its third and fifth phases it will use Incubus Darkness on the member in the top slot of the party, dealing 99,999 damage and inflicting Instant Death, and the only things that can save them are Reraise or a properly timed Jump. Finally, it opens each phase of the fight with Ultimate Lightning, halving the party's current HP, and Ultimate Lightning will use up any Blink effects the party has, leaving them exposed to Ultimate Hold on the very next turn unless you recast Blink instantly. Taken together, this makes for a boss that has very strong attacks, can instantly cripple 4/5s of the party with status ailments and Instant Death, and getting past those moves unscathed requires paying close attention to its AI script and carefully timing your party's actions to nullify them properly.

[[folder: Dragon King]]
* The next level of Cardia content after Dreambreakers with a Bahamut fight for each realm, it's not a huge jump in difficulty like Dreambreaker but it can still be hard. The stats for Bahamut are different for each realm fight with a few moves being different. It has the usual phase change like Dreambreakers where the damage stops before a phase change. It also has the full break debuff that is used a couple turns in phase 1(but it's the mild version fortunately), and Dreambreaker Full Break at Phase 3. The notable gimmick for this fight is the start of phase 2. hHe puts up an uncounterable 99% wall buff for 5 seconds. And around 6 crystals will float around him. The damage and effects his attacks will do depends on how many crystals he has out. Each turn he takes will increase the crystal count up with a max of 8 crystals, but using a soulbreak that uses SB points decreases the crystal count by two. Unfortunately he has moves that can drain SB points so you have to time your Soul Break use carefully. And to further discourage the use of Tyro, any offensive soulbreaks used by off-realm characters will be countered with full break, encouraging the use of in-realm full break buff soulbreaks or non-offensive off-realm characters like Mog. It also adds new buffs to the record board corresponding to the realm characters when each one is defeated. While the VII and Type-0 version of Bahamut are considered among the easiest versions, there's one that is considered the hardest of all of them.
** The XI realm version of Bahamut is regarded as the hardest of them all. The fight is considered to be overtuned for many reasons. He's considered to be among the tankiest by stats alone and having more HP on average, XI banners are very rare, being one of the three Bahamut fights with dispel(the other two being Tactics and V), the lack of in-realm critical fix soulbreaks since Shantotto(and Arciela later on for Global) are the only magic users in the realm, and Aphmau being considered one of the lower tier healers in the game. Needless to say this one tends to be the last one completed by many expert players.

* The next level of Cardia content after Dreambreakers with a Bahamut fight for each realm, it's not a huge jump in difficulty like Dreambreaker but it can still be hard. The stats for Bahamut are different for each realm fight with a few moves being different. It has the usual phase change like Dreambreakers where the damage stops before a phase change. It also has the full break debuff that is used a couple turns in phase 1(but it's the mild version fortunately), and Dreambreaker Full Break at Phase 3. The notable gimmick for this fight is the start of phase 2. hHe puts up an uncounterable 99% wall buff for 5 seconds. And around 6 crystals will float around him. The damage and effects his attacks will do depends on how many crystals he has out. Each turn he takes will increase the crystal count up with a max of 8 crystals, but using a soulbreak that uses SB points decreases the crystal count by two. Unfortunately he has moves that can drain SB points so you have to time your Soul Break use carefully. And to further discourage the use of Tyro, any offensive soulbreaks used by off-realm characters will be countered with full break, encouraging the use of in-realm full break buff soulbreaks or non-offensive off-realm characters like Mog.

** Sin, the FFX Dreambreaker boss. He's considered to be among the most awful of the Dreambreaker bosses. The main problems are with his status effects. He uses confuse on the character in the top slot early into the fight, meaning you have to have someone hit that character or use an ability or soulbreak with esuna, but even worse is that he has petrify, which he uses when you enter his 2nd phase on the character in the 2nd slot which is more or less the same as being dead as curing that character removes every single buff received beforehand, so you need to reapply that to them. Another obnoxious move is that he'll buff his DEF by 50 percent so you also have to have armor breakdown if you're using a physical FFX party which you'll probably do as Tidus and Rikku are very often featured in FFX banners. And because the FFX realm is so focused in water, he also can raise his defense against water based attacks. Of course that's not to say of his general attacks which are mainly gravity based so it will do a lot of damage and some have sap which can easily kill you. All of this makes for a very painful and utterly obnoxious battle to win even if you're stacked with the best relics for the FFX characters. It's slightly easier if you opt to use the mages for FFX to bypass his Defense buff and they don't use water so they don't have to worry about the water resistance buff.

* Dreambreakers as a whole are pretty brutal. They have the same Rage mechanics as 6* Magicites plus the Realm mechanics of the Torments, meaning players are expected to bring teams in all 17 Realms (plus the Core+Beyond Realms) that all synergize well and have strong White Mages and DPS characters, a tall order for many players. The Dreambreakers all share an effect that when they phase change at 70% and 40% HP, all damage inflicted upon them is negated until the current action ends, at which point most of them immediately (as in durign the character's turn and in-between their current actions) use a Full Break attack that reduces the party's ATK/DEF/MAG/RES; the debuff is 40% the first time and 70% the second time, and some even inflict the 70% version the first time too. These mechanics to their phase changes means it is impossible to brute force rush them down like Magicites and Torments could be, because Soul Breaks and ability combos will have their damage nulled and then crippled by the Full Break. The Full Break will also kill the party's momentum without a way to overwrite the buff with an effect that raises ATK/DEF/MAG/RES, but at the time Dreambreakers began no one had such a Soul Break except for Tyro's Overstrike. But them comes another mechanic of Dreambreakers and their phase change, which is to cast an unblockable Stop on any off-realm characters when they phase change, and most of them have a decent MND stat so it'll lock Tyro down for at least several seconds and any non-White Mage-type off-realm characters are basically removed from the battle. All of this meant that Dreambreakers were untouchable without the latest tech that started giving characters Soul Breaks with ATK/DEF/MAG/RES buffs on them, which also limits party compositions since a player will ''need'' to bring such a character with them, even if they were useless otherwise, and build their team to fit them in.

* The 5-stars Magicites are very hard in their own right, but among those, Syldra is just brutal. For starters, like Tiamat, she mixes her Wind element with Lightning attacks, so that you are forced to expect devestating hits from two elements instead of just one. Once she enters her Enraged Mode, she gets a massive boost to damage resistance and ATB bar fill rate, so she'll quickly overwhelm you with pure DPS unless you Dispel her, and her damage resistance makes it difficult to nail an Overstrike hit to break her out of Enraged Mode. The rest of the fight isn't any easier -- she'll use [=NulFrost=] to boost her Ice resistance, will periodically use White Wind to heal herself, and her offense includes Gravity-based percentage damage moves and Wind attacks that lower Wind resistance. When you finally get her to the last 40% of her HP, she'll use "High Stakes" to cast Haste on herself again and give herself a boost to DEF, RES, and MND; because of how stat buffs/debuffs work in this game, you need an attack that lowers those same three stats at once to cancel out the boost, and no one who is actually feasible to fight Syldra had such a move for the longest time. Also in her third phase, she gets a second Gravity attack that deals damage equal to 75% of ''max'' HP, so anyone below 3/4s health is going to hit the ground. The sum result of all this is a boss that moves like the wind, hits like a sledgehammer, and takes hits like a self-repairing brick. Even with Ice Chain and Imperils, Syldra is extremely challenging.

'''Note''': {{Final Boss}}es and {{Wake Up Call Boss}}es are not allowed unless they're overly difficult by their standards. {{Bonus Boss}}es are not allowed; they're optional and have no standards for difficulty.

** Tantarian in the Realm Dungeons is a ''nightmare'', not for its demands or difficulty, but for its mechanic, inherited from its home game. You need to hit for 25%~45% of its max HP in one turn (12~15k for Classic, straight around 20k for Elite) for the book to open and enable you to directly damage it. Brought weapons and abilities that can't do that range of damage by either doing too much or too little damage? [[UnintentionallyUnwinnable Well, you're fucked and stuck in a never-ending fight]].

* Hades of the 4-star Magicites is no slouch either, thanks to his schtick of StandardStatusEffects. It opens the fight with Savage Black Cauldron, doing Resistance-ignoring Dark damage to the entire party and inflicting Doom. For the rest of the fight he'll use the Resistance-ignoring Shadow Flare, and Black Cauldron, which has a 30% chance ''each'' of inflicting Poison, Silence, Paralyze, Confuse, Slow and Sleep: unless you have a character who can cast Astra or Magic Blink on the team, this is pretty much guaranteed to incapacitate the entire party in some manner or another. When Hades falls to 50% HP, he ''immediately'' casts Dispel on your party, and if it comes the turn before he uses Black Cauldron, you're probably going to be watching someone die in short order. Finally, every time his attack patterns shift to his second and third phases, he opens with Savage Strike, dealing physical Dark damage to the entire party and inflicting Interrupt; if you had Astra it just got used up, so you'd better recast it quick before Black Cauldron comes three turns later. Beating Hades requires not just a team with Astra and/or Magic Blink to avoid Black Cauldron, but also constantly monitoring his HP in fear of when Dispel and Savage Strike are coming.

* Dreambreakers as a whole are pretty brutal. They have the same Rage mechanics as 6* Magicites plus the Realm mechanics of the Torments, meaning players are expected to bring teams in all 17 Realms (plus the Core+Beyond Realms) that all synergize well and have strong White Mages and DPS characters, a tall order for many players. The Dreambreakers all share an effect that when they hit 70% and 40% HP, all the damage they take is reduced so that their HP can't be reduced past either threshold until the current player action ends and they do a proper phase change, which means it is flat impossible to brute force them and rush them down like 6*s could be. And when they phase change, they use Full Break, crippling the party; while most of their first Full Breaks reduce the affected stats by 40% and can thus be ignored with a powerful enough party (some of the early DB fights have multiple 70% Full Breaks), their third phase's Full Break is a 70% reduction to the affected stats, sapping the party's offensive and defensive potential just as the boss enters the most difficult phase of the fight. The only way to stop this is a Soul Break that raises ATK/DEF/MAG/RES, which would overwrite Full Break, but at the time no one had such a Soul Break except for Tyro on his Overstrike; enter another mechanic of Dreambreakers, that when they phase change they cast Stop on any off-realm characters, and most of them have a decent MND stat so it'll lock Tyro down for at least several seconds. All of this meant that Dreambreakers were untouchable without the latest tech that started giving characters Soul Breaks with ATK/DEF/MAG/RES buffs on them, which also limits party compositions since a player will ''need'' to bring such a character with them, even if they were useless otherwise, and build their team to fit them in.

** Tantarian in the Realm Dungeons is a ''nightmare'', not for its demands or difficulty, but for its mechanic, inherited from its home game. You need to hit for 25%~45% of its max HP in one turn (12~15k for Classic, straight around 20k for Elite) for the book to open and enable you to directly damage it. Brought weapons and abilities that can't do that range of damage by either doing too much or too little damage? [[UnwinnableByMistake Well, you're fucked and stuck in a never-ending fight]].

* Dreambreakers as a whole are pretty brutal. They have the same Rage mechanics as 6* Magicites plus the Realm mechanics of the Torments, meaning players are expected to bring teams in all 17 Realms (plus the Core+Beyond Realms) that all synergize well and have strong White Mages and DPS characters, a tall order for many players. The Dreambreakers all share an effect that when they hit 70% and 40% HP, they become ''invincible'' until the current action ends and they do a proper phase change, which means it is flat impossible to brute force them and rush them down like 6*s could be. And when they phase change, they use Full Break, crippling the party; their 40% Full Break is a -70% to the affected stats, sapping the party's offensive and defensive potential just as the boss enters the most difficult phase of the fight. The only way to stop this is a Soul Break that raises ATK/DEF/MAG/RES, which would overwrite Full Break, but at the time no one had such a Soul Break except for Tyro on his Overstrike; enter another mechanic of Dreambreakers, that when they phase change they cast Stop on any off-realm characters, and most of them have a decent MND stat so it'll lock Tyro down for at least several seconds. All of this meant that Dreambreakers were untouchable without the latest tech that started giving characters Soul Breaks with ATK/DEF/MAG/RES buffs on them, which also limits party compositions since a player will ''need'' to bring such a character with them, even if they were useless otherwise, and build their team to fit them in.

* Like 5-star Magicites to 6-star Magicites. Dreambreakers is a big DifficultySpike to the torments. They have more health and defenses but the most annoying thing with them is every time they change phases(which happens when you deplete their HP to 70% and 40% and you can't deal damage beyond that until they change phases), they use fullbreak on your entire party crippling their DPS for a few seconds. This more or less means you must slot in a character that buffs the party's ATK/DEF/MAG/RES at least twice in these fights. Fortunately the stats of the bosses that are determined by the number of in-realm characters is lenient enough to allow 1 off-realm character in these fights. Tyro was initially used because his Overstrike Soulbreak was the only soulbreak that could buff those exact stats. DeNA caught on to this strategy and had every boss use Dreambreaker Stop that only affects off-realm characters every phase change starting with the 3rd Dreambreaker boss and Tyro had to have a high mind to shrug it off. DeNA also started adding new soulbreaks for in-realm characters meant to counter the fullbreaks to compensate. However some of these bosses are just very ridiculous in general.

** Sin, the FFX Dreambreaker boss. He's considered to be among the most awful of the Dreambreaker bosses. The main problems are with his status effects. He uses confuse on the character in the top slot early into the fight, meaning you have to have someone hit that character or use an ability or soulbreak with esuna, but even worse that he has petrify, which he uses when you enter his 2nd phase on the 2nd slot, it's more or less the same as being dead as curing that character removes every single buff received beforehand, so you need to reapply that to them. Another obnoxious move is that he'll buff his DEF by 50 percent so you also have to have armor breakdown if you're using a physical FFX party which you'll probably do as Tidus and Rikku are very often featured in FFX banners. And because the FFX realm is so focused in water, he also can raise his defense against water based attacks. Of course that's not to say of his general attacks which are mainly gravity based so it will do a lot of damage and some have sap which can easily kill you. All of this makes for a very painful and utterly obnoxious battle to win even if you're stacked with the best relics for the FFX characters. It's slightly easier if you opt to use the mages for FFX to bypass his Defense buff and they don't use water so they don't have to worry about the water resistance buff.

* Like 5-star Magicites to 6-star Magicites. Dreambreakers is a big DifficultySpike to the torments. They have more health and defenses but the most annoying thing with them is every time they change phases(which happens when you deplete their HP to 70% and 40% and you can't deal damage beyond that until they change phases), they use fullbreak on your entire party crippling their DPS for a few seconds. This more or less means you must slot in a character that buffs the party's ATK/DEF/MAG/RES at least twice in these fights. Tyro was initially used because his Overstrike Soulbreak was the only soulbreak that could buff those exact stats. DeNA caught on to this strategy and had every boss use Dreambreaker Stop starting with the 3rd Dreambreaker boss and Tyro had to have a high mind to shrug it off. However some of these bosses are very ridiculous in general.
** Sin, the FFX Dreambreaker boss. He's considered to be among the most awful of the Dreambreaker bosses. The main problems are with his status effects. He uses confuse on the character in the top slot early into the fight, meaning you have to have someone hit that character or use an ability or soulbreak with esuna, but even worse that he has petrify, which he uses when you enter his 2nd phase on the 2nd slot, it's more or less the same as being dead as curing that character removes every single buff received beforehand, so you need to reapply that to them.

* Following the 6-star Magicites, the game introduced Argent Odin; an even more deadly variant of the Dark Odin fight. Compared to Dark Odin, Argent Odin is considerably more predictable; his attacks are elementally-themed, but they follow a very strict pattern throughout all versions of the fight, as opposed to the many mechanics Dark Odin used from the other Magicites. This doesn't make Argent Odin any easier, especially since he has at least 1.5 million more HP to begin with as well as higher overall stats. Like the 6-star Magicites, Argent Odin resists damage from heroes not using the right elemental aura. And to make matters worse, he will always dispel your elemental auras between phases, sometimes multiple times. Like Dark Odin, he uses Zantetsuken, which is an instant game ender if he does so at rage 3. Stopping this is even harder than with Dark Odin; he always rises to rage 3 the turn before he launches the attack, and he has multiple Rage trigger thresholds in the space between 90% HP and 80% HP. Which is generally where parties at the power level for the fight will tend to be at the time if they're on track with damage. This means that parties will need even more coordination than with Dark Odin to avoid losing to Zantetsuken. Odin also likes to use Antiheal, to reduce the amount of healing party members can recieve. This hamstrings many white mages, and makes the comparatively rare stocked HP effect more valuable, which heals for a fixed amount of HP and isn't affected by things that increase or reduce healing. Upon reaching 75% HP, he will use Achromatic Aegis, which is similar to Syldra's High Stakes; a defense buff that makes it nearly impossible to do meaningful damage for several seconds. Parties will either need to have someone who can dispel that rare buff combo, or lose momentum for a few rounds. Even without that buff, Odin's rages give him a *lot* of defense. Since they deal a fixed amount of base damage, 6-star Magicite summons won't be able to break his rages after the initial call. Once again, you need to beat Odin (and get his Magicite summon) in order to effectively fight Odin, and if you don't have his elemental weakness 6* Magicite in your deck, his damage is increased by 23% and your own damage is reduced by 30%, making it basically impossible to keep up with his damage output or inflict meaningful damage in return. Finally, Odin has mechanics in every fight that ''will'', almost without fail, kill 2 specific party members (either with massive Antiheal, Doom, or the Death spell). Much like stocked HP, Raise effects are comparatively rare and unpopular, so dealing with an unavoidable pair of deaths makes party construction more difficult, so a healer with an Awakening Soul Break, which usually heal, revive and Haste everyone at the same time on use is basically mandatory unless you can somehow finish the fight with just 3 party members. The rewards for Odin are worth the hassle, but only just.

* Following the 6-star Magicites, the game introduced Argent Odin; an even more deadly variant of the Dark Odin fight. Compared to Dark Odin, Argent Odin is considerably more predictable; his attacks are elementally-themed, but they follow a very strict pattern throughout all versions of the fight, as opposed to the many mechanics Dark Odin used from the other Magicites. This doesn't make Argent Odin any easier. Like the 6-star Magicites, Argent Odin resists damage from heroes not using the right elemental aura. And to make matters worse, he will always dispel your elemental auras between phases, sometimes multiple times. Like Dark Odin, he uses Zantetsuken, which is an instant game ender if he does so at rage 3. Stopping this is even harder than with Dark Odin; he always rises to rage 3 the turn before he launches the attack, and he has multiple Rage trigger thresholds in the space between 90% HP and 80% HP. Which is generally where parties at the power level for the fight will tend to be at the time if they're on track with damage. This means that parties will need even more coordination than with Dark Odin to avoid losing to Zantetsuken. Odin also likes to use Antiheal, to reduce the amount of healing party members can recieve. This hamstrings many white mages, and makes the comparatively rare stocked HP effect more valuable. Upon reaching 75% HP, he will use Achromatic Aegis, which is similar to Syldra's High Stakes; a defense buff that makes it nearly impossible to do meaningful damage for several seconds. Parties will either need to have someone who can dispel that rare buff combo, or lose momentum for a few rounds. Even without that buff, Odin's rages give him a *lot* of defense. 6-star Magicite stummons will struggle to break his rages after the initial call. Once again, you need to beat Odin (and get his Magicite summon) in order to effectively fight Odin. Finally, Odin has mechanics in every fight that ''will'', almost without fail, kill 2 specific party members (either with massive Antiheal, Doom, or the Death spell). Much like stocked HP, Raise effects are comparatively rare and unpopular, so dealing with an unavoidable pair of daths makes party construction more difficult. The rewards for Odin are worth the hassle, but only just.

* The boss fight in the 2nd half of Act 2 Chapter 6 against[[spoiler: The Lich]] is considered much more challenging than a lot of the preceding bosses before it. And this is due to it's main gimmick where it puts up a shield that makes it invulnerable to all attacks when it's HP falls under 50% and 20% respectively and the only way to break it is using attacks that break the damage cap. Your only options to do this are Tyro's 2 Arcane Overstrike soulbreaks which can only be used once and Bigg's Ultra chase attack. And if you thought the fight would be over once you deplete his HP? Think again, because he survives and puts up one last shield much like the player would have last stand. You pretty much have to level up Biggs and hit a high enough chain count from Dr Mog's chain so the chase will break the damage cap if you want to win this fight.