That One Boss / Touhou

"Still, is it too easy? Well, I'm about at my limit..."
ZUN on Perfect Cherry Blossom, the only Touhou game to have a phantasm stage - a level above the usual extra stage.

As anyone who has played Touhou will tell you, the boss fights are what these games are all about. There are well over 100 boss characters in the series, and you encounter most of them only once, so it's natural that some make a more lasting impression than others. In fanon, they might be famous for their colorful personalities or ridiculous cuteness levels, but for those who have actually played the games, they will always be fondly remembered for a different reason.

She may not be the hardest boss in her game. She may not test your skills to the same extent as the Final Boss, or your patience and determination like the Extra Boss. Beating her may not even earn you much bragging rights. But she will make your life a living Bullet Hell nonetheless. She is the reason many people have never seen the good endings. She has left countless broken hearts and keyboards in her wake. Even hardened shmup players have been known to reach for the bomb key at first sight of her. She is That One Girl!

Which boss exactly qualifies for the title varies from player to player and depends somewhat on your choice of character and shot type, but generally every game has at least one boss that will make you go pichuun again and again long after you've figured her patterns out. You can always count on them to mess up your until-that-point perfect game. They are mostly found around stage 4 or 5.

NOTE: As always, the Final Boss and Wake-Up Call Boss cannot be That One Boss without being overly hard by their standards. Please do not add them as examples. Also, to avoid cheapening the title, don't list bosses that are only an example on Lunatic difficulty or because of that one spell card you can cancel out with a single bomb. Remember Bonus Boss is completely banned no matter what. This includes Extra stage mid-bosses too.


Highly Responsive to Prayers
  • Although normally pretty easy to beat, defeating Elis flawlessly on Hard mode without taking any damage is a serious achievement. Her erratic attack patterns that occur at unnerving speed and with little to no indication of how they'll behave makes for an extremely frustrating and unpredictable opponent to be reckoned with.

The Story of Eastern Wonderland
  • Marisa Kirisame in her very first appearance as the stage 4 boss. She pulls out four multicolored orbs that all shoot danmaku in addition to the bullets coming from herself. Furthermore, she can cause them to spin around outward in a fashion that is very hard to anticipate and dodge. She becomes much easier when the orbs are destroyed... until she simply recreates them. She is also aggravating due to her tendency to fly down to the bottom of the screen, much closer to the player than most other Touhou bosses, which makes dodging her attacks harder or impossible.

Lotus Land Story
  • Elly, mainly because of her scythe. She throws it at you in the middle of her patterns, which already require a fair bit of precision, it's slightly homing, and it blocks your shots. If you're playing a shot type that can't get around that it'll be a very long fight.
  • When playing as Marisa, there's Reimu in stage 4. She is a nightmare to defeat, since she has several attacks that can either spawn very fast spreads of bullets, yin-yangs which are large and bounce off the sides of the play field in erratic fashions, or wall in the player and force them to dodge fast aimed bullets.

Mystic Square
  • Mai and Yuki, the stage 4 bosses, are pretty frustrating due to the sheer amount of bullet spam coming from two different directions, as well as Mai's laser and small bullets. And that's when you fight them together. Depending upon who received the most damage, you fight the survivor, and it gets harder. Mai uses bouncing ice daggers and egg bullets that break into more bullets when your shots hit them. Yuki, on the other hand, just spams slow and fast patterns, but also uses fireballs that block shots.
  • Yumeko, the penultimate boss of the game, is known for being a nightmare to defeat even for experts. While the difficulty of the game is gradually but steadily raised until her battle, she herself is a nasty difficulty spike. Half of her patterns require very fast reactions - she just throws some knives and bullets. But later, you have to deal with VERY tightly aimed streams of bullets/lasers AND knives she randomly throws everywhere. If you survive that, prepare for some very fast bullet walls followed by more knives... from both sides of the screen! Her final attack, which "only" requires dodging diagonally thrown daggers, seems easy by comparison. And since all of her patterns are speedy and need very good reflexes rather than good bullet trajectory reading, you will usually have to bomb in advance to avoid losing even more resources. Just watch this video...

Embodiment of Scarlet Devil
  • Patchouli Knowledge, the stage 4 boss, is the novice Touhou player's greatest obstacle to completing the game without continues. Her spell card patterns are very random, and she tends to move around a lot, making her a challenge to hit. And God help you if you play as ReimuB, because ReimuB Patchouli is absolutely murderous.
  • If you got past Patchouli, there is no chance to rest, as Sakuya comes very soon after. Her midboss pattern is specifically designed to box the player in. It does not help that she is the first user of that annoying dagger danmaku with a hitbox which seems larger than the actual sprite. Her stage 5 midboss spell card "Misdirection" can drop your lives quickly if you don't know exactly how to deal with it. And then there's the boss fight. She has the gimmick of stopping time, and she'll use this ability to make her daggers harder to dodge, and considering the daggers have a hitbox dissonance, be prepared to lose a couple of lives at least if you don't bomb. Have fun trying to get past her and beat the rest of the game in one single continue.

Perfect Cherry Blossom
  • The Prismriver Sisters come at the end of stage 4, which is already arguably the hardest non-extra level in Touhou. Yet again, the cards they use on you depend on your character choice, as well as which one of them you focus your shots on. Their nameless non-spell patterns fill the screen with a truly ridiculous number of bullets on higher difficulties. These are the same every time, so it's possible to find a safe spot and/or memorize them, but if you get hit even once while dodging them, Dynamic Difficulty kicks in and changes up the pattern, making memorization completely impractical. Even Sakuya A, arguably the best character to use, has troubles with this boss fight, because you're forced to fight Merlin at the start of the Prismriver Sisters battle, all because of her gimmick being homing and curvy lasers, which are supremely hard to dodge, so good luck on that.
  • Once you get past the Prismriver Sisters, there is another difficulty spike awaiting you — Youmu Konpaku. She keeps you company all the way to the final boss as miniboss of stage 5 & 6, but it's her boss battle that's evil. Her favorite method of attack is to throw dense AND rather fast (or just extremely dense) clusterfucks layers of bullets, while giving you about 3 seconds of bullet time to position yourself out of harm's way. In theory. You need a lot of practice to get used to this to the point you won't be reaching for the bomb key during every slowdown. Youmu singlehandely proves that reading-based spells can be just as hard as reaction-based ones. Demonstration.

Imperishable Night
  • Both level 4 bosses, that is, either Reimu or Marisa.
    • Reimu uses heavily patterned, but extremely dense clusters of spell tags, fires off powerful homing shots, and boxes you into small areas with her attacks. In the second part of the fight, she's usually zipping all over the screen, making herself nigh-impossible to hit. Not so hard as she was in LLS, but really hard anyways.
    • On the other hand, Marisa's attacks are much less structured. She prefers to shower the entire screen with her deceptively large looking star bullets. Her first spell card generates spirals of huge stars, showers the field with tiny stars coming in from the sides, and adds periodic shotgun-style blasts from her familiars. Then you get to the second half of the fight...

Phantasmagoria of Flower View
  • Aya Shameimaru. She's fast as hell, and it doesn't help the AI makes her excessively cheap, dodging almost everything you'll throw to her. Usually you will lose one or two lives trying to defeat her, before the RNG goes easy on you and lets you defeat her more easily, but even if you defeat her, you'll have yet to face Komachi / Yuka and Eiki Shiki, which is even worse than Aya in terms of AI cheapness. If the character you're using finds her as your 7th opponent, good luck in trying to clear the game in one credit with that character. You'll need it...

Shoot the Bullet
  • "Seamless Ceiling of Kinkaku-ji". The nightmarish new impossible request of Kaguya Houraisan is impossible for many a player indeed. It starts as a seemingly doable pattern of falling almost half-screen bullet walls and a spinning layer of bullets thrown around the stage to make it harder to approach her. Said layer gets thicker after each successful photo and reaches a ridiculous level for the last one — it's one of the scenes many people simply don't have the patience to clear.

Subterranean Animism
  • Satori Komeiji can be this, depending on who your option is, as she uses that character's spell cards. Heaven help you if you're playing as ReimuC and aren't prepared for "Tengu Macro Burst" to come hurtling at you. If you are playing as ReimuA, then have fun with Yukari's "Border of Wave and Particle", which was part of the extra stage of Shoot The Bullet. And then there's MarisaB (Patchouli). Her torturous water cards are the ones that Satori chooses, even though one of them ("Princess Undine") isn't even one of the spellcards that Marisa remembers from her. Well, those and one of Patchouli's cards from the extra stage of EoSD, the "Philosopher's Stone".
  • Orin is almost universally declared the worst of them all. For beginners, there's the non-spellcards from the cat form in the stage 5 battle. Not so hard as it seems, but you can get clipped easily. Then there's the infamous "Cat's Walk" / "Vengeful Cat Spirit's Erratic Step". If you don't read the card's pattern correctly, well... nice knowing you. And then, there's the actual boss battle. The zombie fairies are the least of your worries. Her third spell card, "Needle Mountain of a Former Hell" / "The Needles of Yore and the Vengeful Spirits in Pain", is really hard to read, due to the spinning ghost wheels, which are almost but not entirely unlike any other attack found in the series, and the bombs are useless against the wheels, so have fun.
    • Her final encounter in Stage 6. For those that played Battle Toads, remember the final part of Stage 3? It's basically that, that is, if you care about the spell card bonus.

Undefined Fantastic Object
  • Ichirin, together with Unzan, in stage 3. Be prepared to deal with Unzan's fists, which are bothersome while you're trying to dodge the other bullets and lasers from her spellcards.
  • Captain Minamitsu Murasa, the stage 4 boss. Giant anchors, literal raindrop dodging, and a homing survival card that requires precise maneuvering right at the end, all at stage four. If she doesn't mess you up, then...
  • Shou Toramaru, the stage 5 boss, definitely will do it. Many people have great difficulty with her, especially with the curvy lasers. Her most notable spell card is Most Valuable Vajra / Vajra of Perfect Buddhism. The spinning homing lasers plus the other bullets make this card insanely difficult. It gives you so little opportunity to damage her, that with certain shot types it basically becomes a survival card too.

Double Spoiler
  • Satori's "Vague Recollection of Kinkaku-ji". See that example in Shoot the Bullet section? Satori, being the troll she is, makes the players relive the horror again. This time, you only have to take 3 pictures... because the spell starts in the hardest mode. And the bullet pattern before the last photo is even harder than the original spellcard's hardest phase.
  • Iku Nagae, the stage 10 boss.note  Though she originated in the fighting game Scarlet Weather Rhapsody, and was not even the final boss in it, practically all her spell cards are a nightmare. Just try capturing "Pearl of the Five-Clawed Dragon" with Hatate, who makes every other card in the game easier. And then you get to "Dragon Palace Messenger's Swimming Shot", which feels downright broken. No strategy or trick works against its combination of completely random curvy lasers mixed with completely random large orbs with big hitboxes. This is the last scene most people clear, usually by pure luck, if at all.

Ten Desires
  • Yoshika Miyako, the resident jiang-shi of Stage 3, has the annoying gimmick of absorbing spirits that emanate from her body to restore health. If you don't get close to her to intercept the spirits, she can easily deny a spellcard capture, even if you are wailing at her health the entire time. In addition, she fires large, spread out waves of kunai danmaku that can be very difficult to deal with, especially with a forward shooting character. And that's not even getting to the problems Youmu has...
  • Seiga Kaku by herself is weak. However, being a Flunky Boss, she decides to bring in a bodyguard...which just so happens to be the previous That One Boss, which makes her incredibly hard to hit. Fortunately, you can take Yoshika out. Unfortunately, she'll come back to life after a few seconds.

Double Dealing Character
  • Kagerou Imaizumi can be a contender of the hardest stage 3 boss in the series. All of her attacks come out very fast, fill the screen extremely quickly, and travel in random directions. “Triangle Fang/Star Fang” covers up 2/3 of the screens with random bullets, “Strange Roar/Full Moon Howling” can screw you up with a fast-moving wall of bullets if RNG decides against you. Finally, "Star Ring Pounce/High Speed Pounce" is a wide area attack that forces you to move around the screen and the boss can ram into you if you decide to stay only at the bottom or get in her way.
  • Seija Kijin, the stage 5 boss. Do you remember Sakuya, Youmu, and Reisen and how their gimmicks screwed many players? Well... she goes one step further, having the power of turning anything over, and she'll be glad to use this ability against you. She isn't as strong as other bosses in terms of bullet spam, but she doesn't need any of that because of her ability. Her mid-boss spellcard fires bullets upwards that then Wrap Around to the bottom of the screen, which screws a lot of players up simply because of how used they are to dodging bullets coming from the top. Then, in the stage boss fight, she screws you over by flipping the screen horizontally and your controls with it in the first spell card and then vertically in the next. The third spell card works a lot like the mid-boss one, with one difference: Bombs are useless against the bullets this time around. Then, for her final spellcard, she rotates the screen 180 degrees every few seconds. The patterns themselves aren't terribly difficult by Stage 5 standards; it's the screen flipping and rotating and breaks from the gameplay norms that makes her attacks brutal.

Urban Legend in Limbo
  • Byakuren, appearing only as the Taoist faction Final Boss. She can and will easily destroy those puny Taoists. The things that makes her hard are her Spell Cards. Almost all of them are ungrazeable, which in Danmaku fighting games means bad news. Her Occult Spell Card, however, takes the cake. It involves riding her motorcycle trying to ram your character, and it is very damaging and ungrazeable. Don't even try to guard it, as she will break it in a second. Worse, her occult orb is right AT the back of the motorcycle, meaning in order to stagger her, you have to be close enough to touch it AND far enough to avoid the motorcycle itself while she's zipping back and forth trying to ram you. Her second Occult Spell Card makes the first one look like Rumia's Spell Card; she's now driving in the background and foreground while throwing projectiles at you before trying to ram you at an even higher speed. As such, she can't be damaged for large portions of the Spell, and can be very difficult to hit without forcing you to eat damage yourself for those few moments that she returns on-screen. Worse, her occult orb is right behind the motorcycle, you have to time your jump correctly in order to touch it. Too early and you miss it, too late and you get rammed for massive damage. All in all, you're almost guaranteed to spend all your lives trying to beat her (for added bonus, you will hate motorcycles after this) until you learn her patterns..

Legacy of Lunatic Kingdom
  • Doremy Sweet, who is developing some notoriety in the fandom in the demo for having brutal non-spells. She has been compared to Stage 5 or Stage 6 bosses in difficulty, but she's only a Stage 3 boss! Her non-spells combine fast and slow bullets, she fires them in a swirl-like fashion, the bullets spin into themselves and you can easily get cornered. Her midboss card spawns bullets close to the player in all angles, her first boss card can wall the player with purple stars, her third boss card has lasers and bullets that bounce from walls, including the bottom one, might as well be an instakill if you are close to the bottom of the screen, her last card can spawn bullets close/on top of the player if it isn't careful. Her only easy attack is her second boss card, which uses fast swirls.
  • Clownpiece, the stage 5 boss, gained early infamy in the fandom for the massive Difficulty Spike. Her initial non-spell is very confusing and then immediately followed up by a survival card. Yes, a survival card. This early in the fight. It even incorporates a massive moon that blocks out some of the other danmaku and forces you to estimate where the stream is going to continue instead of grazing along. Most of her cards somehow incorporate both lasers, some of which are directed at you Byakuren-style, and star danmaku in dense, fast waves which are nigh-impossible to navigate through. Some of her non-spells force you to micrododge to a hair-tearing extent and eats away your resources while you try memorize her patterns. It doesn't help that she uses a second survival-card at the end of her fight, utilizing her signature moons again. Granted, this might be her easiest spell, but like any respectable survival card, it can become tricky in the end. She is the One Boss in a game full of them, seen by many players as being harder than the Final Boss and the Bonus Boss and is undoubtedly one of the hardest bosses in the entire series. She shares with Air Man the honor of having a fanmade song which is primarily about how difficult she is to beat.

Hidden Star in Four Seasons
  • In an otherwise easy game, we have Mai Tereida and Satono Nishida, the bosses from Stage 5. Unlike the rest of the game, except the final boss, stage 5 is a big step in difficulty, which culminates with the appearance of the backup dancers for a dual boss battle. The main problem with this battle are their tricky nonspells, all of which use ofudas. Mai using zig-zagging trajectories, Satono using curving trajectories, both at the same time, so managing a good route can be rough if the RNG isn't on your side. Not only are the nonspells a hurdle though, but there's two notable spellcards in the battle as well. The first being their penultimate spellcard Dance Sign "Behind Festival", which is a combination of Satono's Myōga Blessing "Behind You" and Mai's Broadleaf Sign "Tanabata Star Festival" spells. It has the arrowhead rain and homing ofudas from the bottom of the screen of the former attack, and the erratic falling stars of the latter all in one package. If the RNG doesn't like you, tough luck, that's a life lost if you don't release or bomb. Their last combined spell, Mad Dance "Tengu-odoshi" / "Frenzied Tengu-Frightening", isn't that much better. The attack is also troublesome due to the usage of curvy lasers and straight lasers in conjunction with their nonspell ofudas, which by themselves can cause accidents, and if the lasers aren't positioned just right in relation with the ofudas, it guarantees the need to do extremely precise micrododging, an ability that most players don't have. Add up everything mentioned above and you have a recipe for one ruthless boss fight.

Fangames
  • Labyrinth of Touhou has plenty of these:
    • Chen, of all people, can be absolutely devastating. Thanks to the area you fight her in being full of powerful magic energy, her speed is through the roof, allowing her to attack pretty much every second. And her main attack is an incredibly powerful physical attacks, at a point where over half your party consists of Squishy Wizards. And did we mention she's one of the first story boss of the game?
    • Youmu Konpaku, who is almost guaranteed to give you hell. For starters, she's teamed up with her ghost half who rains down status effects on your party, while she devastates your whole team with her absurdly powerful sword attacks. Thankfully, the ghost goes down fairly easily. Youmu, on the other hand, has a whopping 24,000 HP, with the most you're capable of doing at best is 1000 or so. And about half the characters at your disposal are weak to physical attacks, the only moves Youmu uses, and die to them instantly.
      • Judging by the above, you'd probably think that it's a good idea to focus on the ghost, considering that it has less health. You'd be very, very wrong. Upon it going down, Youmu goes completely insane with her attacks, using her powerful elemental attacks more often and also beginning to use Slash of Eternity, which is ungodly powerful.
    • Suwako not only has a ton of health and constantly swaps between having high physical and magical defenses, but due to how her fight is triggered you will NOT be ready the first time you fight her.
    • The Eientei trio, against whom you must kill Eirin and Kaguya at the same time or else face an instant game-over from either Astronomical Entombing or Danmaku Barrage.
      • Luckily, characters high Spirit Affinity can resist them somewhat, so equipping characters like Komachi with the +128 SPI affinity item helps a lot
    • Yuyuko, a.k.a. "Whoops, here's a multi-target attack with 200% chance of instant death. As my opening move and randomly once my health gets low." This forces you to gear your party members with equipment that has Spirit and Death resistance, which can potentially lower your overall damage output.
    • Flandre, whose Laevatein obliterates anyone not with tankish stats and about 500 FIR affinity. Her Slash Dive also instantly kills anyone not having absurd amount of HP and physical defense.
    • Yukari, who uses Djinn "I totally cribbed this from Golden Sun" Storm to drain all SP from ALL your characters (including those in reserve). And she'll always use it in battle twice, including once just before her Turns Red phase where she starts buffing all of her stats.
    • Rinnosuke, who has an absurdly long fight filled with several different forms, and is capable of inflicting every status effect in the game. To add insult to injury, they can switch between their elemental forms if you don’t damage them enough, and the ones that are inactive regain health. You could have one form on the ropes, only to have Kourin to switch to a brand new form with full health. By the time you take that form out, the first one will have, more often than not, come back to full health. And much like Yukari, his final form has a full buffing move in World Shaking Military Rule, which buffs all of his stats by 66%, guaranteeing a full-wipe when he uses Start of Heavenly Demise as his next move.
    • Bloody Papa. Two words: "Strengthen Jutsu" and “Papa's Washing Machine.”
    • Hibachi #1 and 2, who are like Eirin and Kaguya, only even more unforgiving, and with relatively infinite DEF or MND.
    • Utsuho, who busts out Giga Flare from out of nowhere without any warning at all during low health. If you're not expecting Mystic attacks on a Fire-based boss, then you are screwed.
  • Labyrinth of Touhou 2 has a few fun ones as well:
    • The Lesser Golem FOE on floor 3 is a Luck-Based Mission, simply because, when first met, only Rumia can reliably damage it. And the Golem's powerful physical attack will kill Rumia in one hit. If she winds up taking a hit, your only out is hoping you can debuff its mind enough with Kogasa and inflicts Silence to further lower its mind with Parsee or Kasen that Marisa becomes capable of dealing damage, and even this may not be enough.
    • Komachi is fought on floor 3, before the party has a chance to craft or find a lot of anti-death equipment. While it is possible to make Youmu tanky and resistant enough to deal with Short Life Expectancy (as it only hits your leftmost character), this leaves the rest of the party open to Ferriage in the Deep Fog, a full-party move that can also inflict Death. At low health, she'll do Narrow Confines of Avici to pepper your team with statuses and debuffs before pulling out Scythe that Chooses the Dead, a beefed up version of Short Life Expectancy that can strike anyone in the party.
    • The Lamprey Serpent FOE appears on both floors 4 and 5, well before you're ready to actually kill it. This is because of its Bite attack, which does tremendous amounts of damage and has good delay. The fact that it can start causing instant death below half life tends to not be much of a factor because an unprepared party will likely be destroyed before it can bring the FOE that low, and a prepared party will likely bring the death-resistant Komachi in as the tank.
    • On floor 5 is Hina, who possesses the Biorhythm of the Misfortune God attack to heavily debuff everyone on the field, and then uses Misfortune Reversal to flip her debuffs into buffs before pummeling the party with her party-wide magic. She also counters Heavy, Slience, and Terror by casting Spinning Around More Than Usual, again buffing herself in the process. Old Lady Ohgane's Fire is also her most powerful attack, capable of killing several of your frontliners if you weren’t expecting it.
    • Tenshi Hinanawi on Floor 9 is a major brick wall to most players. She has absurdly high defenses, a variety of moves to cripple your party members and kill anyone weak. Her Sword of Hisou also kills anyone with buffs going over 100%, forcing to keep watch and maintain your buffs moderately. State of Enlightment buffs her already absurd defenses by 100% so you have to debuff her if you want to have any chance of dealing damage to her. Even then, unless you invest most of your stat in attack or magic, you won’t see a huge number inflicted on either. Inflicting Heavy and Silence helps further debuff her defense and mind by half, however, the game never tells you these reduction effects.
      • Her final fight on 12F also pulls a big nuke every turn if she has any debuff at all. Good luck killing Tenshi with high defensive stats without using debuffs!
    • You have to fight in order to recruit Remilia and Sakuya this time (as well as progress, as they block the 11F stairs), and they make you earn it. When her health is lowered enough, Sakuya will bring out Private Square, an unblockable team wide paralyze, to effectively give the bosses some free turns. And if you think you're being smart in reducing the hits you take by going for Remi first, she'll use Blood Drain, which buffs both bosses and steals half of Sakuya's HP, meaning her next action will likely be Private Square. And to top it off, once one boss goes down the other one starts buffing and pulling out the really big guns. Either Remilia beefs all of her stats up with Curse of Vlad Tepes or Sakuya buffs her speed like mad with Luna Clock.
    • The Golden Mirror is when the non-character bosses really start to get annoying. With sky-high defense and lower-but-still-high magical defense and a massive amount of resistance to mystic, spirit, dark and physical. It also gains free magic boost every turn, forcing you to kill it quickly. It's difficult to get good damage in while its Ancient Curse attack rips up anyone with weak magic defense and drops a bunch of statuses onto the survivors. Oh, and it's got World Devouring Calamity, better known as Djinn Storm, to throw at you at 33% HP.
    • The Magatama is considered another brick wall. It has high stats across the boards and gains free speed every turn. It gains a recognition of the only boss having both Black Universe and Half Moon Slash. The former reduces the target’s HP to 1 while inflicting it with various status effects, and the latter halves the HP of all frontliners and kills anyone with 1 HP. Oh, and it's got World Devouring Destruction, which is just like World Devouring Calamity but on your HP instead.
    • Yuuka on floor 8 is absurdly fast and powerful. She can heals and buffs herself. The fight essentially relies on how often she uses Gensokyo’s Reflowering to heal herself by 1/10 of HP. She also uses Master Spark when low on health, which instantly wipes out your party if you don’t defeat her in time and evasion RNG decides against you.
    • Pretty much all Enhanced Bosses are this. They are the super beefed-up versions of all non-Touhou bosses you fight throughout the game, only extremely hard to beat. Their stats are insanely high across the board. Even the easiest Malignut Eater will give you a trouble. Special Award goes to Poisonous Wasp’s Shadow, which has insane amount of attack and speed. Unless you have been grinding at floor 20 and extra floors to boost your level, stat bonus, library point and resistances, you won’t be able to beat them.
    • The fights with Extra Bosses are also this:
      • The Great “C” summons four more clones of itself. You must kill them all before one of them gets a turn or it will respawn all lost ones next turn with full HP. Oh, each one also has an access to Black Universe and mind-ignoring attack. Each one is also invincible until they takes an action on their first turn.
      • The Second Sun has extremely high magic and magical defense. It also can switch your party members’ position as many as it feels like it.
      • Desire-Eating Demon has the highest speed in the game. It has high defense and even higher magical defense. It instantly kills your random party member on the fourth turn and every second turn onwards.
      • Guardian of the Crystals spawns 4 crystals to aid it in battle. Each of the crystal is extremely powerful and can cripple your party in a different way. Fire crystal has insanely high attack, Water crystal dispels your buff, Wind crystal buffs all of its allies and Nature crystal can heal one of its allies. The guardian is also troublesome. It can heal per the number of crystal alive. It has a variety of powerful moves, including Dark Star which dispels its own buff or debuff once it reachs a certain point and deals a heavy damage to you so you cannot debuff the guardian too much. If you decide to kill all of the crystals, the guardian will also spam buffing its own stats and thus casting Dark Star.
  • Patchouli Knowledge in Koumajou Densetsu, lagely thanks to her "Philosopher's Stone" attack which deals a large amount of damage, is tricky to dodge, tricky to follow up with a comeback and follows an attack with homing bullets, making it all the harder to exploit the brief moments where she is open.
    • The sequel has three TOBs. First of all Konpaku Youmu who attacks the player in an area where water reaches up to Sakuya's torso, severly crippling her mobility, and at higher difficulty settings her ghost-half also fires bullet barrages when hit, forcing the player to time his/her attacks to make sure the ghost-half is not accidentally caught in a stray slash. The second example is Marisa, who has likely claimed more extra lives with her laser barrage than any other single attack in the game. The third one is Yuyuko, who has two boss gimmicks: The first one is a red butterfly that slowly follows you throughout the fight and is a One-Hit Kill on touch. The second gimmick is that many of her bullets do not cause Mercy Invincibility, or even make you flinch, so if she nails you with a line of butterflies, you're pretty much dead. In addition to this, she also throws a LOT More Dakka than any boss fought up to this point.
  • Megumi Yaobi, the stage 5 boss from the fangame Marine Benefit. She has the gimmick of flooding the screen while giving the player a bubble to stay in; if your hitbox leaves the bubble for even a millisecond, you die. On top of that, she moves constantly all around the screen, making it very hard to actually deal damage to her. For her last nonspell, she even circles the screen while spraying bullets everywhere. And when you think it's over, she pulls out her survival card, The Eight Million Laughing Gods, which is That One Attack to end them all. It's not unheard of to lose two or three lives to this one card.note 
    • As if this weren't enough, she shows up again as the stage 6 midboss, and deliberately goes out of her way to block your path through the bubbles with the biggest projectile available to her - Megumi Yaobi. If you aren't prepared for this, and are just watching the bullets and the bubbles while paying no attention to the boss, as is typically expected of the player, you WILL die. And even if you are prepared, the attack is nightmarishly difficult to read, considering how the bullets come from absolutely every direction possible for bullets to come from, all at once, without any pattern to speak of. Arguably the hardest attack in stage 6, and the player hasn't even seen the final boss yet.
  • Alice in Paper Tenko. You first face off a giant puppet with 60 HP that hits you for 4 to 5 damage per turn when at this point you'll have around 30 HP at best. Then you face a 50 HP Alice. When at this point your HP was reduced to single digits, Alice will summon mooks constantly so you can't damage her with any attacks except the Celestial Stone Drill, launch said mooks at you for an attack that deals 10 HP damage, 9 if you time your button presses correctly. If you didn't stock on healing items back at Nitori's shop, this will be a very painful battle.
  • Utsuho in her Phantasmagoria Trues incarnation. She's only faced in Unlimited difficulty, but in every other difficulty, you had two options for who you faced in stage 4; in Unlimited, you're forced to fight Utsuho. This is a problem, since despite being only the stage 4 boss, she's actually harder than she was in Subterranean Animism — where she was the final boss! Her danmaku is ridiculously fast, to the point where in some patterns you can get killed by a bullet that didn't exist half a second ago, while her smaller bullets move in very awkward ways and love to wall the player at any opportunity they can get. All of this isn't getting into That One Attack, Suppression "Hell's Helix", consisting of constant shifting walls coming at the player relentlessly from the sides. Or the fact that in this game, Utsuho's suns are entirely hitbox, while in Subterranean Animism, they were almost entirely hitbox — this may look on paper like a distinction without a difference, but in practice, far from it. Next to Utsuho, even Eiki Shiki in stage 5 feels like a Breather Boss in comparison.
    • And then there's Ran Yakumo. She isn't a Bonus Boss in this game, but when you get to Stage 3 on Advanced difficulty, you will desperately wish she was. Her patterns feature enormous walls, so large they can potentially cover a third of the screen or even more, as early as her first midboss nonspell, which is followed by a spell that features walls with tiny gaps coming at you from both sides at once. Then it's taken From Bad to Worse with her actual boss battle, where she greets you with a survival card that forces you to get ridiculously close to the red targeting circles that signify imminent death or else you die instantly — but don't actually touch the circles, or you also die instantly. And it doesn't get any easier from there, culminating in her final spellcard which constantly throws glowing walls at you from multiple directions, followed by a stream of knives that you need to dodge at the very bottom of the screen - when the angle of the walls Ran had been throwing at you made being high on the screen seem like the right strategy.
  • Tarumi Takenouchi, the fifth stage boss of Riverbed Soul Saver. She isn't content to just use one gimmick against you; no, she'll throw something different at you with almost literally every attack she performs. Trying to wall you, shooting bullets at you from every conceivable direction all at once, doing so again while actively chasing you down, throwing giant fists at you, then throwing anchors at you in case you weren't already having horrible flashbacks to Undefined Fantastic Object. And what's her final attack? All of the above at once. Not even Liberation mode is likely to save you here.
    • Not helping matters any is that she showed up as the stage 4 midboss...and she was a total pushover then. After the brutal Wake-Up Call Boss in stage 4, and That One Midboss earlier in stage 5, most new players are relieved to see her as the boss, expecting a Breather Boss fight. They'd be very, very wrong.
  • After the Wake-Up Call Boss of stage three comes Mochizuki Ichiyou, the fourth boss in Book of Star Mythology. She has criminally speedy nonspells and difficult puzzle spells that are borderline unfair to any person going through the game the first time. Most players going in blind lose around three lives by the time her first two healthbars are down, due to the following:
    • Her first attack throws out a huge spread of never-seen-beforenote  warning lines, and in less than a second she then fires ludicrously fast shuriken along those lines, ensuring a player going in blind almost-surely dies immediately.
    • Then her first spell (in Hard/Lunatic) has six/eight clones fire kunai at you such that you must follow a very specific pattern to dodge them.
    • Her second nonspell has her envelop the whole screen with red shuriken, after which she fires kunai at them to have them burst very explosively into arrowhead bullets.
    • Her second spell (in Hard/Lunatic)note  is arguably That One Attack, with actually-impassable walls spawning over and over on the screen as she throws extremely dense kunai waves at you. See for yourself.

http://tvtropes.org/pmwiki/pmwiki.php/ThatOneBoss/Touhou