Probably Monster Hunter World's Fatalis. That's the only fight I've ever had to genuinely grind for multiple days to beat. It was 100% worth it though, the feeling of bringing him down for the first time was unmatched.
For me it was Psycho mantis from Metal Gear Solid. The reason being that I didn't understood English at the time, so it was literally an impossible boss. I got frustrated with it and abandoned the game, until I found a translated version of it and replayed it and he's actually very easy if you know what you need to do.
Ornstein and Smough from Dark Souls.
The series have plenty of difficult boss fights but this one is earlier than most and the biggest difficulty spike in the entire game IMHO.
Outside of the Souls games, there's Lil' Hunter from Nuclear Throne. I tried to beat this little trashcan SO many times and succeeded only once. It's insane.
Also shout-out to Hush from the Binding of Isaac for almost giving me a heart attack when I was fighting it as the tainted lost. Never again.
For me, it was in Last of Us, >!when you walk through the door and get caught in the rope trap, then have to shoot the zombies upside-down.!<
I had to go through that entire animation over and over and over. It made me hate the game. I played a little bit more after finally making it through, but my heart wasn't in it and I just stopped after a while.
In Chrono Cross, when entering Time Fortress Chronopolis, you immediately encounter the PolisPolice. This isn't framed by the game as a boss encounter, but it is.
There is a design problem with this boss that you probably wouldn't see in a more modern RPG. To survive its big attack, you need the White Plate to absorb white-based magic attacks. You get the White Plate by stealing it from the Sky Dragon. If you already fought the Sky Dragon and forgot to steal at the time, you are hosed. The game doesn't let you go back and redo that, and the PolisPolice encounter is about 2/3rds of the way through the game--very late to be starting over again.
I replayed that encounter 20 times before I finally lucked out on the attack cycle to keep the party alive. Then I encountered the actual hardest boss: a disc scratch that prevented the game from continuing towards the very end.
Reminds me of the time in a Pokemon game when a friend of mine caught Latias in one go only for the game to immediately freeze afterward with no explanation.
Oh my god. I tried everything. Every potion combo, every magic combo, every adjustment of Donald and Goofy to make them heal or damage. Never beat her. And never beat the game.
And before that is the fight against Riku with that hours long unstoppable cutscene. "You'll never take Kairi's heart!"
I still have every single line of that “Kairi’s inside me” cutscene memorized, because it was so extremely long and was immediately before the hardest story boss fight in the game. I felt like I was throwing myself against a brick wall with how many times I had to retry that Riku fight.
In comparison, the second Maleficent (dragon) fight was a breeze. I spanked her in like two or three tries, max.
Most people agree that Hollow Bastion is where the difficulty actually spikes. Before then, most bosses won’t really give you any trouble as long as you’re properly leveled. But Hollow Bastion is what separates the “easy” section of the game from the “hard” section.
Okay, i'm gonna name one that might raise some eyebrow.
Halflight, Spear of the Church from Dark Souls 3 Ringed City. I know i know, but i can explain. I'm doing a knife only, no summon run, i mainly use Brigand Twindagger for everything, and occasionally Bandit's Knife for anything susceptible to bleed, and it's quite a good run, beating anything with varying difficulty, and even Demon Prince were defeated with a knife, then comes Halflight, Weeb of the Church. Technically it isn't a hard one because it's basically vs an npc invader, but the difficult came from the constantly spawning Guardian that's also do healing and also using a knife, and also the long reaching and parrying weeb sword of Halflight. I couldn't get past this one no matter how much i try, it's the most difficult "easy" fight i've ever did on this run, where the second most difficult one is...Deacon of the Deep.
For me it was Sword Saint Isshin from Sekiro. The ape already took me days to beat, but Isshin was weeks and hundreds of attempts. But it felt so fucking good - especially since it was easy to no-hit Genichiro by the end. God, he must have been pissed off.
Radagon and Elden Beast at rune level 1. The area of effect attacks and the tracking projectiles are brutal. I was able to get a strategy that clobbered Radagon in <1 minute without taking any hits but it required really intense concentration and timing. Not being able to practice just the Beast was the worst part, I hated having to slog through Radagon every single time to attempt it.
Also Sister Friede at level 1 is a strong contender. I don't remember which took me longer to complete.
Yeah, you have to be perfect and not get knocked off, otherwise its back to square one. Super annoying. But it does feel like a real accomplishment when you finally beat him!
Lies of P - nameless puppet. I choose the other ending on my first run, so my first time facing him was in ng+. Not sure if that made it harder, but yeah, that one was rough
Ahhh keep going, really experiment with creating different openings for attacks. Such a great fight. And then (maybe spoilers, not sure? You probably already know that fromsoft games often have different endings / paths) figure out how to have an even harder version of that fight
Demon of Hatred also took me absolutely ages. Days. But it's optional so really I only have myself to blame.
For me the answer is probably Malenia from Elden Ring. Took so long learning all of her moves and still only made it through by summoning the mimic for phase 2
It's been a long time since I played so my memory may not be totally accurate, but the final boss in fatal frame 2. I rage quit it because it was a one hit kill, and before you get to them, you had to walk down a long hallway avoiding other enemies. It was like 5 minutes of work to get to the final boss only for him to hit you once and you have to start all over. So infuriating. The rest of the game was so much fun.
What an absolute nightmare. They play like an online cheater. It's just back to back sub and special weapons. There's almost no room for error. I gave up after like thirty tries because the reward just wasn't worth the stress and frustration.
So this is dumb but there is a Mummy game, as on the movie, I think on PS2. You could play through as either O'Connell (Brendan Fraser) or Imhotep (he was fun but pretty overpowered). I don't remember there being a difficulty setting but I could be wrong.
I beat it with Imhotep but never could beat it with O'Connell. I want to say the final boss was the Scorpion King. I tried so many times.
The only thing I can figure is I didn't load up on as much ammo, grenades, equipment, etc. as possible and never went back to try differently.
The boss is not particularly hard but you can only face him after a full run on the max difficulty where you will likely use most of your very limited resources before the bossfight, meaning you can only take a couple hits (at best) before dying.
First time fighting Lothric/Lorian in Dark Souls 3. I was playing a mage which was not it for the fight. Also the runback was about a minute which really ramped up my hatred for the fight. On ng+ after a respec to greatsword wielder, that fight is painfully easy. Greatsword effortlessly hits Lothric's hitbox while he's on Lorian's back which trivializes it, but I didn't know that on first playthrough.
There's a lift right at the side of the main entrance into the bossfight arena that cut down the runback time. You can just rest at the dragonslayer armour and then take the lift up right to the entrance, skipping the annoying stairs of enemies.
Second battle with Vergil in DMC 3, Agni & Rudra in DMC 3 and somehow not as hard to beat but incredibly hard to beat well is the Shadow, Griffon & Nightmare battle from DMC5. Beating it on the DMD difficulty gave me that game """PTSD""" where Stage 18 became "that level" to me haha.
Some of the Berserker fights were pretty fucking rough. The one with three separate berserkers (I think two mages and a melee fighter) had me wanting to throw my controller at the screen. Every time I would get an opening on one, I’d get blasted from behind by the other two.
That stupid course in Star Wars Racer where you have to stay on a very narrow ledge. When you fall off you're relegated to a super long detour and basically have to start over because you have no chance of winning if you fail even once.
Hmm. Not sure. Some bosses that immediately came to mind were O&S in Dark Souls 1 and Hume in Eternal Daughter though. I think I had more trouble with the latter, but it's been so long that I'm not sure.
Growing up I struggled for so long on LittleBigPlanet’s Negativitron boss fight, most recently though I spent days struggling with Uncharted 4’s final boss fight (though somehow I had an easier time on Crushing difficulty on my second play through) and Halo 2’s Prophet Boss Fight.
Well, I've never beat Sans from Undertale, but if we're only counting those we did beat... Maybe it's Undyne the Undying from the same game. I'm deducing that from the time it took me, but to be honest there's a boss from another game that came to my mind first.
See, neither of these bosses feel "unfairly" hard because you have to go out of your way to pick the hardest route to face them. There was one boss whose hardness seems unfair and bad, that was the third boss from the first Spectrobe game. This was really out of nowhere. The first boss took me a few tries because I wasn't used to he game mecanics yet, the second was easy, but the third? I had to look up strategies online, make dozens of trips between my ship and the bosse's location, fighting every mob on the way each time to level my spectrobes up in addition to digging up minerocs to feed them; got them from adult to evolved and finally then I could beat it. After this fight, my spectrobes honestly felt overleveled and every enemy from then on felt super easy.
Worst part is, the plot didn't even justify this boss to be so hard. It didn't make it feel important. It wasn't directly threatening a populated planet, it wasn't anounced before it appeared, it was just there, in the middle of the jungle. And your mission was to find a diamond. Not an important and powerful item that's key to saving the galaxy mind you, a dumb simple diamond, of which the only purpose is to be expensive. So why would you, Rallen, of the Nanairo cosmic patrol; charged with protecting the whole solar system, go look for it? Because some rich bastard has crucial information about the krawls and you need this information to go on, but he won't tell you unless you give him this diamond. BITCH, if there was any logic to the plot, I'd be pointing my canon beam at his head and screaming at him to tell me all he knows or else! How dare a human withhold info necessary to save humanity?
Oh, and if this diamond has no particular power, why is a powerful krawl guarding it? It's not! It's just standing on top of it by shear luck, because fuck you.
Undyne was SO DIFFICULT. I got stuck on her after a million attempts and quit. I came back for another gen run a year later and beat her in maybe 10-15 attempts. Finally got to Sans. Tried maybe 50 times. Never beat him. Looked up the ending on YT hahaha