Welcome to the Top 10 Hardest Bosses in the Kingdom Hearts franchise. This top 10 is going to cover every entry in the Kingdom Hearts.
It’s also going to exclude Data Organization fights as contenders. Being notoriously difficult, they could be a top 10 list all on their own.
Number 10. Phantom – Kingdom Hearts
Number 10 to start off this list is the Phantom from Kingdom Hearts. It’s an optional boss that is only unlocked after completing the first trip to Hollow Bastion.
The Phantom is a gimmick boss and its gimmick is annoying but fair. You have to damage the Phantom with the three elemental magic spells.
It has an orb in its cloak that changes colors, Red for Fire, Blue for Blizzard, Yellow for Thunder. There is also a clear/white color that lets you hit it with your Keyblade.
What makes this fight so difficult are two major factors. First is the MP management, if you didn’t pick staff as your starting weapon or come prepared with elixirs this boss is going to be a pain.
The second is that it casts doom on your party. It counts down from 10 and when it hits zero your party members are gone for good, then it casts on you and it’s an automatic loss.
But you can cast Stop on the big clock in the fight. This postpones the doom effect for a bit and allows you to keep your party to help you.
This fight is a time vampire because not only are you actually fighting the clock in the map the Phantom takes forever to kill. Magic does not do that much damage and he has a lot of health on him so his difficulty purely comes from his gimmick, time, and those who are ill-prepared.
9. Hades – Kingdom Hearts 2
Hades is fought in almost all the Kingdom Hearts game. But his boss fight in Kingdom Hearts 2 is probably the most difficult of them.
The fight starts off with you unable to do any damage to him what so ever. You just have to fight until Hercules shows up in a cutscene, then the real fight starts.
What makes him so hard is that Hades can become invulnerable for parts of the fight where he takes no damage. The only way to make him vulnerable is to use the reaction command Aura Sphere with Hercules to knock Hades out of his red form.
Dealing damage to Hades is easy once you get the Aura Sphere timing down. What makes it hard is Hade’s attacks and how widespread they are.
His fireball isn’t too bad if you have good block timing. But when he summons the giant fire orb that constantly shoots fire and creates plots of magma on the ground it becomes an issue.
It’s hard to use Aura Sphere when they keep appearing on top of the fire circles. Hades makes great use of his Area of Effect attacks and it makes the fight harder than most.
Number 8. Axel – Kingdom Hearts: Chain of Memories
This is specifically the GBA version for Chain of Memories. The Re: CoM Axel fight is much easier than it was in the original.
You fight Axel at the beginning of the game and he’s practically a pushover. But the second fight towards the end he’s not holding back and it shows.
His fire attacks hit hard, he moves around very quickly, and breaking his cards is difficult unless your deck is stocked up with majority 0 cards.
He has a Sleight that creates a wall of fire that boxes you in and moves toward you. Breaking it with a zero card is easy, but he usually follows up with throwing one of his chakrams so you get hit anyways.
If you’re running a magic deck full of Blizzards, Axel isn’t too terribly difficult. But he’s really good at breaking Sleights so good luck getting off a chain of Blizzaga or Blizzard Raid.
Number 7. Terranort – Kingdom Hearts: Birth by Sleep
This is the final boss of Terra’s story in Birth by Sleep. And he’s difficult in the way that fighting a charging bull is difficult.
Terranort moves around constantly and the only time he’s stationary is when he’s using Shotlocks. He rushes around the arena and effectively rams into you most likely interrupting anything you were doing.
It’s almost impossible to fight Terranort without a block command equipped, Heal Block is recommended. You can block Terranort then proceed to wail on him.
But once his health drops low enough he does as all final bosses do and start throwing out a super move. His, in particular, throws comets around the arena that explode on impact.
These aren’t to difficult to dodge but if you slip up once then the fight is basically over. They’ll all come at you and recovering from it is almost impossible.
Number 6. Mysterious Figure – Kingdom Hearts: Birth by Sleep
Another Birth by Sleep boss is the optional boss Mysterious Figure. This is an interesting one because you can fight this boss with either Terra, Ventus, or Aqua and he’s hard with all of them.
Mysterious Figure is a big gimmick boss with a lot of annoying little tricks he throws out. One of his most annoying is where he can freeze time and recover from a hit then immediately hit you take most of your health.
Each of the three characters you can play has different strategies and builds you can do to work against him. But unlike some of the other bosses in Birth by Sleep, Mysterious Figure isn’t one you can just spam Ignite and win like Vanitas.
What adds to the difficulty is how much he moves around. He’s very quick and takes no time getting up to you throwing out combos.
Dodge rolling and blocking works well but half the time he’ll have a combo string going that’ll hit you after the fact. He’s one you really gotta learn and practice to get good at.
Number 5. Young Xehanort – Kingdom Hearts: Dream Drop Distance
Very similar to Mysterious Figure we have Young Xehanort from Dream Drop Distance. He’s the final boss of that game and he has reason to hold that title.
You fight him as Riku and unless you have a decked out command deck with just a ton of Ballonra and Balloonga this fight is a major pain. He has some similar moves to Mysterious Figure but he’s not holding back anything anymore.
Young Xehanort is a close range and long range fighter having attacks that can cover both distances. He can move around quickly and even summon copies of himself.
At a point in the fight, he summons a clock that different versions of himself come out of and attack Riku. It’s a bit of an endurance test to damage the clock while dealing with Xehanort.
Balloon spells make this fight much easier but it’s still a greatly difficult boss fight. Young Xehanort follows the theme of the final bosses being fairly hard and a little annoying.
Number 4. Ansem, Seeker of Darkness – Kingdom Hearts
The final boss of the first Kingdom Hearts is probably one of the longest in gaming history. If we’re being extremely technical the fight has eleven different stages/forms.
You start with Ansem and his guardian, then a Darkside, then Ansem/Guardian again, then giant Ansem, then a heartless horde, then turrets on Ansem’s ship, then heartless, then the ships head, then heartless, the ship’s core, then finally giant Ansem again.
The Ansem fight is more a battle on your patience than anything else. And it is not easy at any point either so it pulls no punches.
The first forms of Ansem are probably the most difficult. He moves around a lot and lets the guardian do most of the damage.
It protects Ansem from being hit at some points and lets him quickly move across the map and out of distance. At some points, the Guardian will possess Sora when hit and make him take damage over time.
This form happens twice, then you deal with giant airship Ansem. He’s not that hard only time consuming and a little annoying.
The gimmicky sections are easy enough, fighting heartless is easy and dealing with the ship head is no issue. Dealing with the main Ansem body gets difficult in the end because of the constant lasers firing at you.
He also as a move where the guardian behind him drains your MP and a giant orb sucks you away from Ansem. He takes forever, you’re gonna burn through all your items, but he’s one hell of a final boss.
Number 3. Roxas – Kingdom Hearts 2 FM+
Roxas is a boss that is only in the Final Mix+ version of the game and he is probably one of the hardest in that version. You have to fight him with just Sora and his moves are devastatingly powerful.
He has two that he typically starts with and defaults to. One is a delayed move where he throws out a blast of wind in all directions and the other is a fast combo swing.
Blocking these are the best way to get some damage in but the telegraph for these moves are very similar. So you’ll sometimes make the wrong defense expecting him to use a different move.
Once you deal some damage he flies into the center of the map and starts firing energy at you. You have to run around the map dodging them until he stops.
After this, the real hard part starts. Roxas continues his normal attacks but now has laser walls that form around him in all directions making it insanely hard to even get close to hitting him.
These lasers are what makes this boss so hard and it can get infuriating especially on Critical mode. He can be taken down with good block timing, some items, and good use of the Limit Form but it takes all of your concentration and ability at the game to beat him.
Number 2. Lingering Will – Kingdom Hearts 2 FM+
Another Final Mix+ exclusive, Lingering Will is known as one of the hardest bosses in KH history. His health is insane, his attacks deal crazy damage, and it is extremely hard to telegraph his moves.
Lingering Will has a massive arsenal of attacks he can use and they’re hard to keep track of. He can turn his Keyblade into his glider, make it huge, turn it into a giant cannon, turn it into a whip, and several other things.
Getting close enough to hit him is hard enough. Getting close enough to hit him, get a full combo off, and actually deal damage is a whole other story.
Lingering Will by all rights could be Number one on any list but he takes the second slot simply because he can be looped into a defeat. Now, Kingdom Hearts bosses have a history of being able to “Cheese” some of them, but Lingering Will is the worst offender.
By equipping Negative Combo and the Fenrir Keyblade, you start the fight then use Donalds limit command. Once Lingering Will is hit by it all you do is jump and attack. And that’s the loop, jump and attack once and repeat the process and as long as you don’t lose your rhythm or miss then you win.
Number 1. Sephiroth – Kingdom Hearts
Now, there is a very good reason Sephiroth is the hardest boss in Kingdom Hearts. It has nothing to do with him simply being Sephiroth, there’s a reason KH2 Sephiroth isn’t on here he’s down right laughable compared to the first game.
What makes Sephiroth so hard to fight is the fact that even going in fully prepared you’re still going to be at a disadvantage. He starts off with more health than you actually see in the beginning, you have to keep wailing on him until his health finally starts going down.
But getting close to him to hit is the issue. Sephiroth’s range with his sword is ridiculous and one hit will drain half to all of your health.
If you don’t have Second Chance or Once More you will very likely be one shot with every hit. Aside from his basic combo, he summons pillars of magma around him that force you to back off.
As the fight goes on he starts using his infamous Heartless Angel move that drains all your HP and MP at once. This makes the fighter harder and forces you to use items like Elixirs.
Toward the end of the fight, Sephiroth will start summoning meteors that float around and do just as much damage as everything else. And the fight just lasts forever because of how tough he is.
But what makes him so hard is the KH1 controls. There is a big difference between the first Kingdom Hearts and every other game after.
The camera controls and game mechanics make this fight far more difficult than it has to be. Kingdom Hearts is by no means perfect in the control section and this fight is a good example.
You can get in some good damage by using moves like Strike Raid and Sonic Blade. They make you invincible and do damage but cost MP.
So they’re a great strategy but become harder to use when he starts using Heartless Angel. You’ll be burning through Elixirs in this fight but beating him is insanely satisfying.