I’ll start by saying that this remake of the game was just as unnecessary as Final Fantasy XXth Anniversary Edition. Sure, if you want the absolute best graphics this game can get, then it delivers: everything looks crisp and shiny. There’s also an additional short sequence at the beginning and some script tweaks, but none of that changes or improves the core gameplay or story, which remains the same as in the Soul of Rebirth edition. Which is to say: pretty good and far better than the original, at least.
The Soul of Rebirth additional storyline is still there and still accessible once you finish the main one. This version’s main addition, just like in FF XXAE, is an extra optional dungeon and superboss. The difference, however, is that, while still being somewhat tedious, the optional dungeon – which is called the Arcane Labyrinth – is much less punishing than the one in FF XXAE and actually has a semblance of a storyline, thus making it more interesting. What’s more, by dint of the way the dungeon functions, you don’t actually have to do everything in one go, but can split your explorations throughout the story.
Here’s the gist: you can obtain “ultimate” weapons for each character in the party, including the temporary ones. Meaning that, you would have to obtain the weapon while they are still with you to get any use out of it. So you can actually make your first foray into the Arcane Labyrinth when Minwu joins the party. What’s more, it also means that you’ll be sending Minwu, Josef and Ricard off to Soul of Rebirth with considerably better weapons, thereby dramatically improving their chances of survival once you get around to it.
FF involved time travel, and the Labyrinth of Time in FF XXAE was based on (*gasp*) time. FFII makes heavy use of keywords, so the Arcane Labyrinth is based on just that. The Labyrinth itself is split into three sections, each with its own entrance. The North West Quarter is near Salamand and has four floors, with Tiamat as the final boss; the North East one is near Bafsk and has seven floors, with Beelzebub as a final boss; and the South East one is near Kashuan and has ten floors, with Black Dragon as the final boss.
In order to access a floor, you will have to enter a keyword from among the ones you’ve learned. Each keyword corresponds to a specific floor with its own specific task to complete. You will also be able to learn some new keywords within the Labyrinths themselves, provided you use a specific sequence of keywords (e.g. use “Dreadnought”, and you’ll be able to learn “Aquifer”, “Cave”, “Wizard” and “Candelabra”). Each character has a list of “favoured” keywords, which you can determine by speaking with one of the mages at the entrance of one of the Labyrinths. You need to use as many of those “favoured” keywords as possible to obtain that character’s ultimate weapon. There are also five “lucky” keyword pairs: if you use one, then the other, the corresponding floor will have no random encounters.
Once you’ve cleared all three Labyrinths, you’ll be able to access the Arcane Sanctuary, situated near Poft, where a character called Deumion will summon the optional boss Phrekyos to fight you. Phrekyos’ level will depend on how many passwords you’ve learned from the main storyline, so there’s no risk of facing an overpowered version when trying for, say, Minwu’s or Josef’s weapons. Once you beat Phrekyos, Deumion will give you a reward. If you’ve used enough “favoured” keywords for a given character, it will be their ultimate weapon.
So basically, you need to optimise your keyword use not only to unlock new keywords within the Labyrinths, but also to use as many “favoured” keywords as you can for the character you’re trying to get the weapon for. Towards the end of the game, once you pick up Leon and have all of the keywords, you can unlock a sequence of floors which will give you some backstory on Deumion and a key item. When you next speak to Deumion after that, you will be able to choose between two new spells as a reward: Revive and Destroy. Revive heals *everything* on the screen (including enemies), but leaves the caster with 0MP. Destroy kills everything on the screen (including allies), but leaves the caster with 1HP and 0MP. It will one-shot most bosses, but it’s also a very hefty price to pay. What’s more, you will actually have to fight Deumion if you want to obtain it, whereas he will simply give you Revive, hinting that that is the correct outcome. It’s pretty obvious from his backstory anyway, and you don’t even get a Bestiary entry if you do fight him. I guess it’s a bit of a twist on the superboss trope.
In the end, by the time you’re able to obtain them, neither spell will be particularly helpful, but Revive can be a good way to start a battle, if your party is a bit banged up. If you do decide to get Destroy, though, make sure you obtain all the weapons you want first…
As you can see, there is a fair bit of repetition involved if you want to get every character kitted out. But the major advantage of the Arcane Labyrinth over the Labyrinth of Time is that there are no timed puzzles, and you don’t need to have a specific sequence of successful or failed puzzles either. You do need to know the keyword lists, but those can easily be found online. All in all, even though it’s unnecessary, this is a better remake than the FF XXAE one, so if you’ve never played FFII before or are simply looking for the best, most up-to-date and most easily available version of the game, this is the one to go for.