Spoiler Warning: Plot details follow. Read at your own risk.
As I askt, you have presented the Offering to the Princess and restored her Humanity. My feelings for the Princess were at Odds with my Plan to rule over Armoroad... I wavered... But you resolved that. And so, I am again the Almighty Father, Mother of the otherworldly Sea. We shall end this now. Rejoice! Your long Journey filled with Hardship, is at its end!
Eldest One speech, Etrian Odyssey III

Progenitor is one of the three possible final bosses on Etrian Odyssey III: The Drowned City. It's fought on B16F (A blowing, bladed wind) and is the hardest of the game's final bosses, and possibly, the hardest final boss on the series. In order to face it, you must follow the Eldest One Route.


The feeling of guilt of what he had done was consuming the Eldest One, holding his powers at the bay, and stopping his invasion on Armoroad. It decided to redeem its past mistakes with Gutrune, handing her the Porcelain Offering, thus preventing the blood of the Deep Ones transforming her into a monster, and also stopping the fight with her brother. By having no restraints, the eldest one finally was able to restore its power, escape its prison, and returning to its true form, as the great father and mother of the Deep Ones. The only thing standing in his way of Armoroad's domination now was the very explorers that helped him in achieving this goal. Knowing that they would come to settle things, he simply sat in his room at Abyssal Shrine. As soon as they found his hall, he finally assumed his real form, the Progenitor, and engaged them in the final battle, to decide the fate of mankind.

(For more detailed info about this character, check the Eldest One.)

Progenitor (Etrian Odyssey III)Edit

The almighty Father and Mother of the Deep Ones, he is a minion of an otherworldly god.
Enemy Data
HP 18900
AT 58
DF 55
EXP 50000
Skills Thorn Cutter, Vine Rush, Dark Breath
Items Abyss Crystal
Weakness None
Resistance None
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This boss is extremely tough, and, by no means, should be taken lightly.

To start with, his attack pattern is completely random, there is no way to know how it will act next, meaning you will have to be ready for anything, anytime.

Its main form of attack are his elemental spells, all of them dealing heavy damage to the whole party, and having a nasty secondary effect. Frozen Eye deals ice damage and lowers your team attack power. Nothing to worry about much, it's the less dangerous of the three. Spine Blaze inflicts fire damage and has a high chance of binding the whole body (if not partially), likely preventing the use of any skills, which may prove to be extremely dangerous, should it affect your healer or the Hoplite protecting the party (if you have one), and should be healed at once. A Monk with Unbind or lots of Theriaca A are a must in this fight. Its most dangerous elemental attack, however, is Death Thunder. Not only will it deal more damage than the other two, but it also has a high chance of Petrifying. Unless one has a Hoplite with a high-level Anti-Volt or a Zodiac with Volt Prophecy, this attack will rip your party apart with extreme ease, probably petrifying anyone who survives the spell. If you lack both of those, make sure to at least have Prevent Order on both rows.

It has some very powerful physical attacks too. Thorn Cutter deals very heavy damage to a single target. The damage is high enough to easily kill mages and low-to-medium defense fighters, and you'll probably need to revive someone after that. Dark Breath is dangerous too, dealing very heavy damage to a target with splash damage to nearby characters. Vine Rush is its most powerful physical attack, dealing heavy damage randomly to 3-6 targets, two of those being enough to kill most weaker characters.

Once its hp gets below half, it will start using two new attacks: Accumulate and Liberate. Accumulate is the most dangerous one, and the one who crushes most parties. It simply doubles the damage of its next attack (cannot be dispelled), whether it be magical or physical. This coupled, along with Death Thunder or Vine Rush, will likely spell the end for even sufficiently prepared parties. Liberate recovers its HP and lifts its bindings and debuffs, although it only uses this skill if it is struck with more than two bindings/debuffs.

For starters, you must have a way to nullify volt elemental attacks, with either Anti-Volt or Volt Prophecy, lest you be annihilated by Death Thunder. If you chose to use Anti-Volt, a Hoplite with the sub-class of a Ninja may help with protecting the rest of the team.. A good healer is important too, as are TP recovery items, Nectars, and Theriacas. Remaining on the defensive for the beginning of the fight works well, but once it starts using Accumulate, your defenses will fall, so the best thing is to focus on dealing damage later on the fight. Having powerful damage dealers is important. A combination of Charge and Star Smasher is capable of removing a quarter of the Progenitor's health, but it is advisable to use it later on in the battle. Charge, Attack Order, Berserker Vow, and Fore Honor are helpful on increasing damage, and skills like Meteor, Front Mortar and Nine Blows can be useful too. Excessive binds and debuffs are not recommended since Liberate will recover a lot of HP.

Skills Edit

  • Accumulate (Uses None): Double the power of its next attack, be it physical or of elemental nature. Only starts using when HP is low.
  • Liberate (Uses None): Removes debuffs/binds of himself and recovers HP. Doesn't use it very often, unless bound or with low HP.
  • Dark Breath (Uses Arms): Very heavy, non-elemental damage to a target with splash damage.
  • Thorn Cutter (Uses Arms): Extremely heavy, slash based damage to a target. Often a one-hit kill, especially if Accumulate used before.
  • Vine Rush (Uses Arms): Heavy, piercing based damage to random targets. 3-6 hits. Very dangerous for low defense characters.
  • Death Thunder (Uses Head): Very heavy, volt based damage to the whole party. High chances of petrifying. Without a doubt, its most dangerous attack, if you are unprepared and unlucky, it often means an instant game over.
  • Frozen Eye (Uses Head): Very heavy, ice-based damage to the whole party. Reduces everyone's attack power.
  • Spine Blaze (Uses Head): Very heavy, fire-based damage. High chances of dealing all the three bindings to the target.

Drops Edit

  • Abyss Crystal (Worth: 11200 en)
  • None.

Conditional Drop Edit

  • None.


  • Progenitor is the first final boss of the series who isn't/wasn't a human before the story.


Their Own Brand of Justice

Their Own Brand of Justice

Etrian Odyssey 3 final boss theme, Their Own Brand Of Justice