Basic notes
1 HPLV runs
You might as well do these together, since to make it through either of them you'll need to have unlocked enough of the Stat Matrix to have high stats regardless of Level and HP. Personally, I do them at Proud as well, so I can get that done as well. Make sure to equip Oathkeeper as your Keyblade, and have Auto-Life active whenever fighting a boss - they still have as much HP as ever.
Chapter 1
Chapter 2
Speedrun tips
1 HPLV tips
The first portion of this level is rather easy at 1 HP. Like any other 1 HP run, save often, and when you have to fight swarms of Heartless, focus on long-range attacks—only use a Keyblade or close-range attack if there are few enemies, and your other commands are depleted.
Sweet jeebus the Keyhole is terrifying at 1 HP. Don't attempt it unless you can Glide and Air Dash. Your biggest danger here is getting hit by the falling blocks, so you should stay on the lower platforms as much as possible. You can tell when a block is coming by the screen shaking, but I'd honestly recommend watching a video playthrough so you know exactly when they're coming. The fallen blox are still dangerous if they fall on you even after they've landed, so make sure you destroy them from the top down.(Ed: insert video link and list of falling blocks here) When you see groups of Heartless, use one of the special commands to take them all out at once.
- After the first Ice Darts - get to the right, then use Wind Spin to destroy the fallen block.
- Some more during the later half, but by staying on the lower path you avoid them completely.
- The first elevator in the second district.
- The first patch of land after the elevators in the second district. Destroy the Shadow, then go to the right edge of the screen and hug it.
- After an upside-down L of Prize Blox after some more platforms and Red Nocturnes.
- At the start of the diagonal elevators.
When you manage to get through all of that, you have to deal with the Guard Armor. No matter how strong you are, you will not be able to kill him with your Keyblade before he puts you down. The trick to defeating him at 1 HP is to instead use the Ice Darts special command to damage him, while staying away from him and avoiding all of his attacks. Do this, and you'll never have to go through this crap again.
Etc.
I'm going to do this. I'm seriously going to do this. Going to make myself do it.
Chapter 2
1 HPLV tips
Everything up until the Keyhole is rather easy, and you can even spend your time getting all sixteen Inklings without much worry. When you get to the Queen's Court, youmight want to use Triple Pursuit to disable the Card Soldiers. However, the Keyhole is...impossible, if you try it like you should in normal gameplay. For this run, you need to totally abandon combo shots, and just fire your Shotlock rapidly and continuously. If you're worried about Yellow Operas (which are the only threat here anyway), go ahead and grab an Aero Shield when you pass it. Otherwise, just incinerate everything in your path. The trickiest part is when you get to the Metal Blox rings in the third stage. Honestly, it's easiest to just hug the left or right of the screen, but if you want to go through them, you need to just do a minimum hop to make it.
When you fight the Trickmaster, you will want to use combo shots, but he should still go down very quickly. Make sure to dodge his fireballs, though.
Anyway, just keep firing like mad, and you'll make it through.
Chapter 4
Speedrun tips
For the speedrun, you'll want to equip a deck of Aero and Thunder-based commands so that you can use Zeus's Spear and Breath of Zeus to clear out crowds. Once the chapter starts, make sure you choose to challenge the Coliseum at 5 layers. You don't need to worry about breaking Blox or Heartless unless they are in your way, so just go straight to the floor exit, and you'll even have time to save in the Save Room.
The biggest thing to remember is that when you get to the fourth layer, go straight for the door. Ignore Cloud completely, and go straight against Cerberus and Hades. You should be able to get through them easily enough, but equip a Strength-L if you need to.
1 HPLV tips
Just like with the speedrun, your deck should be composed solely of Thunder and Aero-based commands. However, you do want to break every Prize Blox to keep your Commands usable. You must use your commands, without compiling them, if there are more than three Heartless per party member (so, if there are four Heartless while it's just Sora, use a command), but I would recommend using it when there's one-less than three per party member too (so, if you have Sora and Hercules, use commands when you fight five Heartless), just to be careful. You should be able to break every blox like this, which will give you a high score at the end of the level and fill your checklist for whichever difficulty you're playing on.
You can never let an enemy get a sneak attack on you. If they do, you've basically just lost. Always attack Heartless head on, or leave the room completely.
Make sure you get Cloud. The more chances you have to attack, the better.
When you get to Cerberus and Hades, make sure you use a Strength-L. You can also use an Autolife-L on Sora if you want, but you shouldn't need to. String together three of your commands to create a Subjugate, and watch the Hound of Hell go down in one hit. Do the same to Hades, and he'll go down before he can even attack.
Chapter 7
Speedrun tips
Personally, I did the speedrun at 1 HP, because you have to ignore Matrix Power collection to go fast, but that means that your strength is so low. Plus, you barely have any HP anyway. It's pretty easy to make it through this with 1 HP, but the bosses are brutal. You'll need to have the Oathkeeper equipped with Auto-Life, and enough Ethers and Hi-Ethers to make sure you are always at LV 3 Clock.
For Data-Riku, I used Zantetsuken, Judgment Triad, Triple Pursuit, and Triple Firaga. Just avoid his attacks as best you can. You should be able to keep a steady LV 3 Clock just by using these commands, but if he ever starts Dark Aura and you are at LV 1 or 2, use an Ether or Hi-Ether to get you to LV 3 immediatley.
Sora's Heartless is...awful. For the rail-shooter beforehand, you should be able to get through everything easily enough, until you get to the Damage Blox that go diagonally across the screen, or the ones that fill most of it up. When you see those, immediately use Lightning Arrow or Aero Shield (Ed: check these names) to get rid of them or go through them.
For the boss himself, focus on Judgment Triad, Triple Pursuit, and Triple Firaga. As long as you stay safe, you should be able to keep from getting hit during his Neo Darkside form. When he turns into an Anti Sora, keep throwing long-distance commands at him, but make sure to dodge often and keep your Clock up. (ba-dum-psshh) It will take some luck, but you will be able to take this guy down.
Chapter 8
Questploration
Hollow Bastion
Avatar Sector
The hardest part of the Avatar Sector is building it. You can use the communications exploit (Ed: remember to add info on the exploit to that article) to populate exactly fifty floors with default characters, but for the other forty, you'll need either a lot of friends or a lot of time. If you don't have that many friends, you're going to just leave your DS on, on tag mode. This will easily take up ninety hours of gameplay.
Now, you'll have to farm Tag Mode to get all 99 Puppies, but NEVER DELETE RANDOMIZED AVATARS. It takes forever to get even one replacement back. Once you've gotten all of the fifty default avatars (listed here), simply delete their floors and use the communications exploit again, but ONLY FOR THOSE FIFTY. It may take many, many rounds of tag mode and deletions, but eventually you'll have all 99 of the little bastards.
For the Avatar Sector itself, I recommend equipping the Ultima Weapon>>>>, with Clock abilities set to Heavy Blade, Undo, Attack Haste, and All Critical. As for your deck, I usually use Curaga, Zantetsuken, Gravity Drop, Judgment Triad, and Eruption, but you can replace Zantetsuken and Eruption if you want. For floors that require you to use Magic commands, I use Flame Fall, Triple Pursuit/Icicle Mine, Exo Spark, Cyclone, and Curaga.
If the floor requires you to ignite Heartless, equip the Wishing Star with Fire Counter; for freezing, equip the Oblivion; for jolting, equip the Olympia; for air-tossing, equip the Three Wishes. You will not be able to hinder Heartless like Defenders or Red Nocturnes, and you can't hinder Large Bodies when they jump on you or Fat Bandits when they shoot fire at you. Otherwise, just use your commands on Blox or un-hinder-able Heartless like these to build up your Clock Gauge, and once you have the correct Counter ability activated, go find something like a Soldier and just keep using Guard over and over.
The rest of the Avatar Sector is pretty straightforward. Its important to remember, though, that only the decim floors multiply your SP - fulfilling challenges on any other floor simply gives you an Avatar Part, so don't worry about the "play at night" or "play on the weekend" challenges if you're doing a 100 floor run. Furthermore, if you're going for huge amounts of SP, you don't have to kill every Heartless and break every blox—especially on the later floors, even an incidental hit from a Heartless will take huge amounts of SP away that you simply can't recover except by scoring a multiplier on a decim floor. Getting all of these multipliers is necessary to get the higher-tier rewards like D-Blizzaga and the stat chips, which are honestly the only thing you'd do this for anyway. Make sure to wager 50% every time. However, the top floors of the Avatar Sector are a wonderful place to farm EXP, so if you're going for Level 99, go ahead and kill everything you see. Encourage your inner psychopath.
(Ed: insert list of the decim challenges here, with tips on how to beat them)
For Eliminators...honestly, by the time you are ready to attack the Avatar Sector, you should be able to murder them easily. They are nothing compared to the regular Heartless you'll see on the final floors. Simply stay behind them and unleash your strongest commands. However, even on the final floors, most Heartless can be killed in one shot by a maxed Gravity Drop or Judgment Triad, though you should still make sure to dodge their attacks. Your biggest worries are bugged Wyverns or Invisibles, which as heavies are immune to Gravity Drop, and especially when yellow or red, can take off up to 10000 SP in a single bout. Keep your distance, and abuse Judgment Triad or Triple Pursuit. If you can trap one in a Keyblade combo, go for it, but try not to get hit.
The biggest feature of the Avatar Sector is obviously the bugged Data-Riku, but he's nowhere near as cruel as the bugged Data-Roxas. For example, his Dark Aura attack can be easily avoided by simply falling through the air, provided you start from high up enough, and you can always dodge normally if you land. Make sure to keep your health up, and simply attack him with Zantetsuken or Judgment Triad. Gravity Drop and Eruption are pretty useless against him, and the top-tier Magic Commands don't do enough damage. Like the bugged Data-Roxas, Data-Riku will go through every phase of being bugged, but unlike that cheating bastard, he never becomes immune to damage, and you should be able to take him down after several successful Judgment Triads.