These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Knights in the Nightmare
Anticlimax Boss: Piche, anyone? She goes down in 1 or 2 hi skill attack, and can't be helped that they give you Frabela and Amalgun/Ulrich to fight her with, who are rather ridiculously high level for the stage they appear in; even if you did not recruit anyone, you can pull it off.
Note that this is only on Easy mode. On the higher difficulty levels, her ability to heal herself practically makes her That One Boss.
Many of the battle music as well. Each bosses also have their own Villain Song.
Fanon Dis Continuity: In what is becoming a running gag on LiveJournal, part of the fandom has refused to acknowledge Atlus' translations of character and place names. May be justified, as Sting published official romanizations long before Atlus' announcement that it would localize the game.
Fridge Logic: ...Why doesn't Alier have wings like every other Tiamat?
Game Breaker: Marietta's staff and the dark feather item can turn Maria into this in Maria's route.
It's actually better to call her Boss Breaker, since you get her back in Scene 28 then lose her after Scene 30 for the rest of the game until the final two Scenes. That's a grand total of 5 Scenes of Game Breaker power, 4 of which are Boss Fights. A single EX-Skill can chop off an enormous portion of a Boss's health bar.
Mellia has the White Feathers item in her own.
Goddamned Bats: Any number of fights that quickly devolve into a mad dash to avoid dozens of projectiles that will blast your Wisp into oblivion.
Demonic Spiders: Those dragons and hellhounds dammit. The former can turn your already tough Bullet Hell into a much worse scenario, the latter...well, they can attack your knights and make them lose vit by quite a large chunk. Those gremlins are rather easy to kill too, but they are hated much due to the Interface Screw they cause.
Goddamned Boss: Nearly every boss that isn't That One Boss, due to one reason or another (usually their special abilities). Examples include Dotaurus (very hard to stop his Hound summon), Scoppio (because you're running on a timer to find a certain plot-important item with a boss who can destroy it breathing down your neck), Leonil (because he cheats by having multiple weapons, and thus multiple bullet attacks), Viena (because this boss has powerful attacks and moves a lot]], Sachitto (because the area is VERY restrictive on both your movement and attack)... Fortunately, a lot of these don't quite reach That One Boss because they may have low health (proportional to how far in the game you are; a boss with not even 20000 HP 3/5 of the way through? Yikes) or bullet attacks that are not too hard to dodge.
Guide Dang It: In order to get the good ending for the first campaign, you have to recruit a certain character...in a hidden level. Yeah, good luck figuring that one out on your first play through.
Inferred Holocaust: Surprisingly enough, inverted — while we only see Wilmgard and Algiery reunited in the best endings, those darn side materials have it that almost everyone was fine; the knights never died in the first place, after all. Only the characters who were explicitly killed stay dead.
Internet Backdraft: The name changes for the English version. Some can be justified by character space ("Staehelingum" to "Staehel"); others can't. Which are better—and which should be used on a given page—is bound to cause arguments, as parties on both sides are slightly opinionated.
Jerkass Woobie: Yes, Meria's a bossy, violent nutcase. It's also implied that she's got some serious issues underneath all of that.
At the very least, Johanna and Diora (from the Second Order of Knights) form a Romantic Two-Girl Friendship. Considering they're both well beyond the age at which such things are typical, it's probably more. Particularly apparent if Johanna is transsouled into Diora.
Johanna: "I'd be happy to become a part of you, Diora...."
Moe: Vienya. So moe you died. "Endless Cute", indeed.
Primea, Piche, several of the young female knights, and even Maria and Mellia.
As an addendum, from the same troper, this point IS rather moot if the player doesn't mind not getting scored. Though getting a Vit increase after getting Ancardia would have been very welcome, this limits her Game Breaker potential even more so as to create some balance. After all, if she had, say, even just 20.00 Vit, wouldn't we all eschew careful unit positioning in favor of repeatedly nuking the entire map? And besides, she DOES gain loyalty a lot faster because all you´re attacking with are normal attacks,Hi-Skills and Ex-Skills.
Tear Jerker: The fates of Algiery and Piche. Some of the other knights' deaths can qualify, as well.
That One Boss: Gunther, who can one-hit-kill any one of your characters. If Maria/Mellia happens to get hit by that attack, it's instant gameover.
The second-to-last boss, Zolgonark, is immensely annoying due to his built-in regeneration stat, which lets him recover thousands of HP at a time as long as the head that has that stat is alive. We sure hope you've powered up Maria/Mellia for this one.
Also, freaking Marietta.
Melad Margus, the Final Boss. Why? It has the highest HP count in the whole game (even more than the Bonus Boss, whose health count was already an exaggeration by that point), it has devastating attacks that will kill your timer in the blink of an eye, it can move pretty fast, the stage is even MORE restrictive than Sachitto's and it's attack cycles are so short that, if it uses its second bullet, it can use another attack before the previous attacks is even done. Even repeating Bullet II just once can be devastating, as it leaves you unable to do anything but dodge the mess of random bullets that it causes. Not even the super-high level Maria/Mellia will be of much use because of the stage design. The only way this fight can be made less annoying is if you're playing on the red path and found both Ancardia and the Dark Feathers, in which case Maria's EX-Skills will do a HUGE part of the work for you.
Though all classes save the Lance Knight (which Crozeph and Darshan happen to be) are gender-especific. This means all Duelists, Hermits and Priestesses are female, and all Warriors (one of which is Werner), Archers and Wizards are male. Lance Knights are the only class where you'll find both men and women. Interestingly, the Archer class was first planned to be female-exclusive, but since the designers wanted to keep a gender balance, it was changed to male-only after the Hermit class was decided to be a female class.
Wangst: Yes, Algiery, we know you have every reason to mope. Please do something other than mope once in a while.
What an Idiot: There's a reason some of the fans sum the game up with "Marietta is a tard".
The Woobie: Nordich, Piche, and several of the knights qualify.
And Maria. Watch her beat herself up over and over for what Marietta did, and see how long it takes before you want to cuddle her and make it all go away. Let's have a show of hands for how many people got just a little misty-eyed when she posted that tweet about wanting to be loved.