Ah, yes, RosenkreuzStilette. This franchise brings so much nostalgia to those who have played classic games such as Mega Man and Castlevania. There's not even a single doubt that such a nostalgic series also has some despicably tough bosses that you'd find within the different adventures in the series. In fact, these guys and girls are the main reason why this series is Nintendo Hard, and why many players have been humiliated withseveral references to classic computer and video games on their respective stages' Game Over screens.
NOTE: Final Bosses and Wake-Up Call Bosses are not to be added unless they're overly difficult by their standards. Bonus Bosses are not allowed; they're optional and have no standards for difficulty.
In discussions about the game, all the bosses in Count Michael Zeppelin's Castle are mentioned frequently, especially the Cross Wall. This thing is similar to the Mecha Dragon from Mega Man 2, and for good reasons; you have to fight it on only a few block platforms above a bottomless hole, and the Creepy Cool Crosses and energy balls it shoots at you travel across the screen rather quickly, and not to mention, once they're above or below you, said energy balls can split in two and its two sections can travel both upwards and downwards. And what's worse? It shoots even more of them once it Turns Red.
It gets even worse when you fight it as Grolla, due to the fact that you'd have to get up close to it to actually damage it with your slash attack. Yeah, compared to the one in the main game, this thing in Grollschwert is a complete and utter bastard.
And the Deviled Egg, a.k.a. the Yellow Devil from the Mega Man series, appears in Iris' fortress. Remember how hard the original Yellow Devil was in the original Mega Man game? This guy's basically the same thing. The pieces of its body fly across the room so fast that they can be hard to jump over or slide under quickly. Its weak point is its eye, just like the Yellow Devil, except it opens up all over its body quite often, making it hard to hit. Oh, and what about when it turns red!? Yep, this thing has a new twist that makes it different from the Yellow Devil; once it turns red, it'll start flipping everything upside down every now and then, and vice-versa! The flipping has the same effect as the waterfalls from before the fight; once you're flipped, your controls are reversed, which means dodging its attacks is harder. Oh yeah, and playing Grollschwert gives it a huge difficulty spike when fighting it as Grolla in comparison to fighting it as Spiritia.
Before that, there's the Bosspider, who's surprisingly just as tough as the boss of the same name in the original Mega Man X and its remake, Maverick Hunter X. The difficulty of figuring out where it will stop when it crawls down as well as the short amount of time it takes to shoot its red core before it closes back up, as well as its increasing speed as it takes damage, all explain it all. Oh, and there are also spears on the walls on each side of its arena.
Freudia Neuwahl is also a major jump in difficulty from the other seven bosses (at least in her stage; in the Opening Stage, she was a Warm-Up Boss), what with her ability to throw more snowflakes than a Touhou game. Worst of all, her weakness weapon only knocks off half of her HP before draining completely. After that, you'll have to do the rest yourself. Assuming, of course, you didn't use it on the Quickman deathbeams earlier in her stage. Oh, and did we mention her stage itself is also That One Level thanks to said death beams?
Freudia becomes harder in the rematch at Iris Stage III, for solely one reason: The arena the fight takes place at. Dodging her more dangerous attacks was somewhat easier because her boss stage was the most spacious out of all other bosses. The rematch stage feels cramped in comparison, her two most dangerous moves taking up the whole screen, leaving little to no room to dodge.
Even if she's not about as tough as Freudia, there's no doubt that Grolla herself, as a boss, is still quite hard. Her unpredictable movements, as well as her fast tackle attack, can take off your health much quicker than you can say "plot device". And that's not all; her multi-cross-cut laser-like slash attack comes out fast and hard to avoid. Oh, and even if you use her weakness weapon, Trauare Wrede's Klageharnisch, she still isn't easy.
It can also be noted that both Freudia and Grolla are the only two bosses that aren't weak against their own weapon in the first game.
As Spiritia, Trauare Wrede's attacks requires precise timing if you want to avoid getting hit by her Leviathan lunge and Klageharnisch. If she hits you with Leviathan, you'll likely lose one-third of HP in a single hit! It doesn't stop there; once she turns red, she'll unleash her Doppelgänger Attack to follow her during her lunging attacks, making this fight require some cat-like reflexes to dodge Trauare, slide under her first doppelgänger and almost immediately jump over the second. Worse still, should you be too far away from her from her initial lunging attack, she WILL double back and lunge at you again, while her doppelgängers follow suit, to make sure she hits you! Even worse still, If a player is unfortunate enough to gain too much distance from Trauare after dodging her attempt to thrust her Leviathan into you again, it's possible she'll repeat this attack to ad infinitium until she hits you!
However, she's much easier if you take the low route in her stage. If you fight her there, the arena will be filled with water, giving you much more leeway in your jumps, and all you really have to worry about is not jumping too high into the spikes on the ceiling. The rematch in the penultimate stage doesn't have this luxury, however.
Spiritia in Rosenkreuzstilette Grollschwert takes Grolla's place because Grolla is playable in that mode. At first, she's not all that bad, but when she turns red, she becomes much worse than Grolla herself was as a boss. Her Freudenstachel attack becomes annoying as hell when you're on the ground, and she can also aim her Lustatem at you if you're climbing the walls of the area, which can also be annoying. And if you think that's bad enough, when she gets close enough to you, she'll call forth her charged Klageharnisch attack. Since Klageharnisch was Grolla's weakness weapon in the main game, the resulting blast from her charged Klageharnisch may even kill you instantly!
The first phase of the fight against Raimund Seyfarth pits you against his fast-flying scythe, Grassense. Grassense can be a pain because it flies around so fast, and in addition, several smaller scythes can also come flying at you really fast, which reminds players of how tough Death himself was in the Castlevania games (particularly to the original 1986 game and Rondo of Blood). Once you've done enough damage to Grassense for Raimund himself to turn red and face you head-on, though, the rest of the fight isn't too tough, unless you go ballistic and try to attack him when he's not doing his Grollschwert rain attack only for him to counter your attack with his own laser slash attack, of course.
In the hands of a skilled player, his counter-attack in his second phase can be used as an A.I. Breaker. However, really only works for Spiritia and the trick to exploiting his counter-attack will require some practice to develop a rhythm to avoid getting hit (or take little damage as possible).
In the C75 and C76 trial versions of Freudenstachel, Grolla has easily proved to be the toughest boss in said demos, even tougher than she already was in the first game. She throws even more Sword Beams when she Turns Red than she did in the first game, and even more during her multi-cross-cut laser-like slash attack, in addition to being able to climb walls and attack you from above. And worst of all, the ground is slippery from the bloody rainstorm just like the last two rooms before her.
And she's still pretty tough in the full version, and rightfully so. Just as you enter the boss room, she surprises you with a fast and long leap to the top of the wall you came in from and comes down to pull off her Sword Plant attack, which can catch you off guard if you're not careful. She is fast and her attacks are hard to dodge, even if her new multi-cross-cut laser-like slash attacks are now predictable.
In the full version of Freudenstachel, we have Schirach Fühler. Every time she jumps and lands on the ground, she causes an earthquake, which wouldn't be so bad, except she does it all the freaking time. And sometimes she creates earthquakes simply by standing and striking the ground with her hammer. And if you're ever stunned by an earthquake, she will grab you and send you flying with a painful Megaton Punch. Her other gimmicks include falling rocks and hurling huge boulders that are difficult to avoid. Worst of all, her weakness, Freudenzwinger, can be somewhat tricky to land, as it ends the moment Freudia gets hit, and you only have limited weapon energy.
Dolis Warmind can be pretty tough as well. Seeing that Freudia, who was previously the hardest of the RKS bosses in the first game, is now playable, it's rather fitting that Dolis take said position in Freudenstachel. Dolis is fast and unpredictable and loves to surprise players with hard-to-dodge attacks and leave them not knowing where she'll strike next, which makes her a pain in the ass to take down. Not to mention, her Fesselspirale attacks are pretty fast as well.
As with the Deviled Egg back in the first game, Devil fights are never fun, not unlike those in the Mega Man games, and the Dark Devil, the One-Winged Angel form of Eifer, is definitely no exception. Remember how the Shadow Devil functioned in Mega Man X5? This beast acts the same way, even if it's not as bad as the Deviled Egg was. However, once it turns red, it gains a new attack that creates a wind that slowly pushes you along the floor as its body pieces fly across the screen a la Deviled Egg, which can make them tough to avoid. And if you think this thing is tough enough for Freudia, wait until you fight it as Pamela, because this thing can be a NIGHTMARE for her.
Speaking of Pamela, she as a boss in the main game has a pretty intense fight of her own, which is basically what Grolla aspires to be. She's insanely fast, and her attacks can easily catch you off guard. She jumps and teleports around a lot during the battle, making her hard to hit. Her fire dash attack is fast as well, and she gets even worse when she turns red. The fact that her weakness weapon, Weißteufel, doesn't slow her down doesn't help, either.
Zorne took a serious level in badassery in this game. She went from a fairly linear boss who threw bombs that were easy to dodge if knowing the right timing to it, to an ungodly fast bomb-throwing Cute Bruiser who jumps around the walls either to strike with her gauntlet, or to jump over the player to throw bombs that now explode upon contact with each other should another bomb be thrown, which happens frequently, making her attacks fairly unpredictable. While not as hard as most examples mentioned in this page, Zorne certainly becomes a trickier boss compared to the first game.