Guns are a recent invention.Very recent. In fact, the technology to make guns, gunpowder, and bullets were taken from the ruins of Shinjuku within the Labyrinth of the first game. Found, studied, and sold. Within a few years they have become popular weapons in some circles, becoming common enough to be sold in shops by the time the second game comes around.
Dark Hunters learn their techniques by studying salvaged "technique magazines".They generally aren't aware of their "original purpose", though clearly more than a few might suspect that their techniques weren't always used against monsters... But that sort of thing got lost in translation, After the End.
Etrian Odyssey III has an all-new roster of heroes because plot-wise, the player's Guild from Heroes of Lagaard can't return. And they won't, because...While your Guild could easily make the jump from Etrian Odyssey to Heroes of Lagaard, certain endgame events make such a reappearance unfeasible — mainly, their 'involvement' in the immortality project. While your heroes are meant to be blank slates and everything about them hinging solely on your imagination, that sort of ending demands some sort of follow-up if they return... which is exactly why they won't. Regardless of whatever path they decided to take with it, it'd be impossible to please everyone — what might work as "perfectly in character" for some players' Guilds to do would invariably prove "horribly OOC!" for others. End result: one majorly Broken Base, something a niche series like Etrian Odyssey can't afford. So while some mention might be made — possibly even allowing your Guild in III to be inspired by them, a distant branch, descendants or cousins or what have you — they won't enter into the main plot so as to avoid another Chrono Cross-ish incident.
Playing the Third Game Will Have Actual Physical Side EffectsWhen I saw the first info, screenshots, and trailers, I couldn't help but feel something bad might happen when playing. This is aside from the headbanging difficulty. Having an unexpected third installment to a much beloved series with the ability to be on a boat would be really exciting.
In EO III, all the inhabitants of Deep City are YggdroidsThe Abyssal King mentions that the Deep Ones feed on human emotion, which is why he cut off contact with Armoroad. Since Seyfried himself is an Yggdroid, we know its possible to transfer your consciousness into an Yggdroid body. Likely all the people who came along with him had their consciousnesses transferred into an Yggroid body as well.
Agata or Hypatia was revived once the body was brought back to town.Why didn't they just ask someone from your party to do it? Agata's too much of an Idiot Hero and Hypatia was too griefstricken to think of it.
In the upcoming Fourth Game, the Labyrinth itself will be the Large God. The games in the series seemed to have a pattern going, in which an element from the previous game turns up in the next. In the first game, Visil was revealed to be the man behind the Yggdrasil Project conducted nearly a thousand years ago. In the second game, the Overlord was experimenting with humans with the Holy Grail to try to grant immortality to other humans, which Visil in the first game had in Type II form, and uploaded himself into a machine to continue his experiments. The third game has Abyssal King Seyfried, who uploaded his consciousness into a mechanical body around the time of the Calamity, similar to the Overlord. Since the Sixth Stratum boss of The Drowned City was Abyssal God, the Man Behind the Monster Lord and was the actual Sixth Stratum, it would make sense to bring that on a much larger scale in the fourth game, considering the Japanese subtitle, translated, is Legend of the Large God.
At least one of the Special Classes will require the balloon to unlock.While exploring with the balloon will still be optional, like sailing was in III, there will still be much more to do with it... including discovering the Hidden Elf Village of one of the Special Classes, enabling you to convince some of them to support your cause.
The Mystics of IV are distantly related to the Forestfolk.And they know what happened to them.
Future Class SpeculationGuesses for what sort of classes could appear in EO V and beyond go here!