Disney and Square Enix together? A killer combination. Disney, Square Enix, and a horde of Wake Up Call Bosses together? Might probably just kill you.
- Kingdom Hearts:
- Riku on Destiny Islands is one of the optional bosses made to practice your combat skills at the start of the game, and is the toughest one of them. He’s very fast and strong for that part of the game, has a brutal counterattack, and can serve as a challenge even for those who already beat the game. Fortunately, losing to him in the duel has no effect on the story (defeating him gives you a Potion), and losing to him in the race will cause the default Gummi ship to be named the Highwind instead of what you chose to name the raft.
- Leon, the first boss of Traverse Town, is also likely to hand Sora his ass on a first-time playthrough. Similar to Riku, losing to him does not affect the storyline. It does, however, award you some bonus experience on victory, and a Megalixer from Aerith, but the item only comes after you fight...
- The Guard Armor in Traverse Town. Not only does it have five separate and powerful body parts that each complete with its own life bar, it also comes at a time when you don't have the Cure spell or that many items. If a player hasn't done any amount of level grinding, Sora's stats won't be terribly large, and he won't have access to his first ability (which comes at level 9, and you're expected to be at around level 5). Also, it is the first time you get to fight with Donald and Goofy and realize how generally useless they are at first. In addition, unlike Riku or Leon, you have to win.
- Cerberus. The bosses before him are either simple enough, or difficult, but not necessary to win. Cerberus marks the point where bosses stop going easy on the player, sporting dirty attacks (particularly snapping at an attacking player), and more HP than anything else at that point. It's especially nasty if the player follows the difficulty levels of the worlds, since they won't have the Cure spell at this point. Fortunately, although it may not appear so, you don't have to fight Cerberus when you first see him. You can leave and come back another day, when you're stronger.
- Clayton from Deep Jungle, especially if you didn't follow the recommended level order, and do Deep Jungle first. It's the first boss that required a significant amount of focus, and use of the dodge roll, even on normal mode. Clayton could hit like a truck, had a ranged, difficult to dodge attack, and when you got close to him, he jumped all the way across the boss arena. Then in phase 2, he summoned a Heartless to ride, who had a ton of health, and also hits very hard. Then the Heartless and Clayton split, and you had to deal with phase 1 Clayton's abilities, and the Heartless' abilities, plus a new ability for each, painful eye-lasers on the Heartless, and a heal on Clayton if you didn't keep him stunlocked. Luckily you only had to kill Clayton, but holy hell.
- Later, the second Parasite Cage battle in Monstro is the mid-game boss, and is much harder than even Clayton and Cerberus, and it's also where the game begins getting more serious.
- Kingdom Hearts: Chain of Memories
- The Trickmaster in Wonderland can be a very dirty one of these if you've been relying on summons and slights, requiring you to space your cards out accordingly and using the right combinations at the right time.
- Larxene. After fighting several simpler battles in the different worlds, Larxene shows up and reminds you that Axel was only pulling his punches, by being able to move insanely quick an deal several fast and painful knife combo attacks and sleights. The 3D remake made it easier to use dodge roll, but she's still one of the more difficult bosses.
- The third battle with Repliku. He uses Dark Aura (not as frequently as his fourth encounter), giving you a taste of what's in store for you during his final battle.
- And then Larxene and Axel serve to remind you that Marluxia is still stronger than them, and this time, they aren't pulling their punches.
- Kingdom Hearts II:
- The Twilight Thorn actually hits pretty hard. This can be bothersome, because it launches a number of attacks at you, and the reaction command function, which you're supposed to use to defeat it, has only just been introduced. The only target you can hit on it is several times higher than you can jump, it rarely puts that part close enough to you to attack, and you only have 2 potions to your name. And need we remind you, this is the first boss of the game.
- Shan Yu is another one of those bosses that forces you to learn a certain technique that you're really going to need later in the game. In his case, it's parrying. If you master the technique of waiting for him to attack (and he telegraphs his attacks), countering them, and only then attacking him, he's quite easy. But try to button mash your way through the fight against him and he'll shrug off everything you throw at him and shred you.
- Demyx, while not a difficult boss to actually fight, has time challenges that make him That One Boss, and like Parasite Cage he's the mid-game boss and is where the game gets Darker and Edgier than it already is.
- Xaldin is considered the hardest boss in the game for where he is fought at, but he serves as a reminder for how powerful the rest of the members of Organization XIII are.
- Birth By Sleep has two.
- Dragon!Maleficent with Aqua. Not nearly as hard as she was in the first game, but still very difficult, given that she likes to spray fire everywhere, and only when you're right behind Prince Phillip can you avoid it, and even use a little reaction. Also, her physical attacks do quite a bit of damage as well.
- The first duel with Vanitas if you're playing Ventus or Aqua (Terra gets to play with Braig instead, who's highly annoying but not particularly hard); where all bosses before him are basically big mooks that can be spell or shotlock spammed from afar or stunned with a reaction command and wailed on endlessly, Vanitas has his own spells he can fire back, can't be stunned, and always teleports out of a combo before you can finish and hits you from behind. The trick is not to combo or spam him, but play it safe and get a hit in before running away and repeating.
- Kingdom Hearts: 358/2 Days features the Infernal Engine as this. Up until that point, the heartless have been predictable and even the new ones were mostly Elite Mooks. The Infernal Engine's introduction is throwing Beast against a door - a pretty good hint of where to go. The Infernal Engine is more or less where the game takes its gloves off, and serves as a great warning that a few more dangerous bosses will come.
- Kingdom Hearts 3D [Dream Drop Distance] has Rinzler, the boss of The Grid for Sora. He has a lot of HP, can easily escape your combos, and turns the screen upside down, reversing your vertical controls. Whereas all previous bosses could be easily defeated with flowmotion attacks or spells, Rinzler can easily escape flowmotion and hounds you constantly.
- Kingdom Hearts III starts off simple enough. The first few bosses are "Get Back Here!" Warm-Up Bosses that are generally incapable of defeating you even if their attacks land. Then you travel to Arendelle and run into Hans’ Heartless; Sköll, a giant ice wolf that has a ton of HP, moves quickly, and hits like a freight train. Not only that, but he can summon small Wolf Heads that not only pester you with bites, but distract you from the bigger target. And if that wasn't enough, he even has a Desperation Attack where he summons an entire pack of Wolf Heads and you're tasked with defeating them before he slams the sun on your party for a Total Party Kill. The good news is, if you stop the attack, he is stunned long enough for one or two good combo strings. The bad news is, if you don't defeat him quickly enough, he can perform the attack again. Sköll is the first boss that truly teaches the player the importance of timing their defensive moves, dealing with crowds of enemies, and dealing with powerful Desperation Attacks, which are skills that will come in handy not only later in the game but also on Critical Mode.
