Persona 3 Nyx Guide

Persona 3 Nyx Guide: Final Boss Battle Explained

Nyx is one of the most iconic bosses that are in the Persona series, which is a daunting task on its own. Each of the JRPGs has dozens of bosses that you fight across the course of their insanely long stories, from both humans to the otherworldly denizens of the Persona universe.

Of them, though, few can live up to the hype and wonder of the central focus of this Persona 3 Nyx guide, in my opinion.

Nyx Avatar is the final boss that you fight in the main story of Persona 3, ignoring The Answer and other sequel storylines.

This Persona 3 Nyx guide is going to break down this wild and immensely challenging boss, including every aspect that you need to know.

From the history of this boss in the lore of the Persona games to a detailed breakdown of how to defeat it in battle, here’s everything that I think you need to know. Please bear in mind that there will be many spoilers for the entire game in this guide.

Bottom Line Up Front

Nyx Avatar is the final boss that players face at the conclusion of Persona 3 in all game versions, from the original to the Portable version on PSP. Excluding The Answer, Nyx is the final send-off moment for the SEES group.

Nyx’s goal is to end all life as we know it through the use of the Dark Hour. It is the very incarnation of the Death Arcana, and there are many personifications of it, including Death, Thanatos, Ryoji Mochizuki, and Pharos.

It is also one of the most challenging bosses to defeat since it has a whopping 14 phases to it. But it is worth it for the chance to summon Thanatos afterward.

See also: Comprehensive Persona 3 Thanatos Guide.

What Is Nyx Persona 3?

Nyx is the final boss that players face off against at the very end of the primary Persona 3 storyline.

It is the final goal for the SEES organization that stands between the members and closes the door for good on Tartarus and the Dark Hour. It is the source of those machinations and the harbinger of the end of life as we know it.

At the same time, Nyx is also one of the most challenging bosses you can fight in Persona 3.

Though there are, technically, some more challenging bosses that players can face after defeating this foe and are considered the “ultimate bosses” of Persona 3, there is no doubting that Nyx is by far one of the most gruesome foes that you can face.

Nyx is the very personification of Death, and the end of the world, representing one of the most challenging bosses fights in the Persona series and JRPGs as a whole.

It is tough to take it down, and there is a massive time commitment even to have a chance of doing so. There is also an insane amount of grinding and preparation recommended for this fight.

Without a doubt, defeating Nyx and beating Persona 3 is an accomplishment as the player has to earn the right to roll credits on this JRPG.

At the same time, Nyx Avatar is also complicated in its characterization. It is not simply the bad guy but a collection of different identities that make it up.


The appearance of Nyx is one of the most confusing parts about the big bad and one of the most spoilery sections.

Though it has a singular appearance in its final boss fight, many different characters and personas make up what Nyx is. Beware some spoilers for several main characters of Persona 3 in this section.

Nyx Avatar

Nyx Avatar has a terrifying appearance that struck my very soul and made it unforgettable. The horrifying look for this final boss starts with the most prominent part, in my opinion: the face.

If you get scared easily, you may not want to look at this beast’s face.

I think it is pretty similar to Nanika’s face in Hunter x Hunter if you’ve read or watched that manga and anime series.

It is a pale, ghostly face with empty black holes where the eyes and mouth should be. The creepy smile makes for a creepy facial expression that is haunting to look at.

Nyx has human-like hair that is spiky and flows out with a bizarre crown-ish accessory on its head.

It carries around two intelligent devices that sort of look like pillars mixed with a massive key or chess piece on both arms. There are similar pillars that stick out from its body.

It wears parts of a black dress, but most of its body is obscured by the black and blue webs of darkness that cover most of its body.

This expands from head to toe, corrupting the body and even making up the two insanely long wings that Nyx has. There is an overall demonic and otherworldly appearance to the harbinger of the end.


Another look for Nyx has to do with its appearance when it is Death and Thanatos.

Though technically two different characters that make up the same being, they have almost the same impression. Thanatos is the more known one and the Persona that players are even able to acquire.

Thanatos is a strange and unique-looking Persona that is wearing a dark blue outfit from top to bottom.

There are white pants that it wears alongside the blue uniform and gloves. It carries a long sword and sheath. Its face is expressionless, with a silver metal skull helmet covering its head.

The most significant part of Thanatos is the massive coffins with characters embedded in them worn around its neck like a strange necklace that is almost as big as it.

The ring of coffins even looks like the wings of Thanatos, the god of death.

Ryoji Mochizuki

Ryoji Mochizuki is the most human appearance for Nyx. He is a young man with whom the player can connect in this form. He wears black dress pants and matching shoes, plus suspenders on top.

He wears a long-sleeve white shirt with a little checkered pattern where the buttons are and slightly rolled up sleeves.

Ryoji wears a yellow scarf around his neck and has a kind but mysterious face to him. His eyes are gray and sad, showing a glimpse of the darkness that is lurking underneath.

His hair is the most exciting part as it is black and spiky but well-kept. It is essentially the same hair as what Nyx has but not messy.


Besides Ryoji Mochizuki, the other human appearance for Nyx Avatar is Pharos. This intriguing young boy has the appearance of a locked prisoner, which is highly symbolic of the being he represents.

Pharos has the appearance of someone roughly nine or ten years old.

He wears a black and white striped prisoner-style uniform from head to toe, with the only exception in his garments being the sandals on his feet.

He has hugely pale-colored skin that makes him look sickly. His ocean blue eyes are large, in stark contrast to his tiny nose, mouth, and eyebrows.

His hair is a muted dark blue color, almost the same as the male protagonist’s hair in Persona 3 but with a messy but short style.


Being that Nyx Avatar is divided up into several beings, it has a strange personality. Starting with Nyx itself, there is little to its character besides its overwhelming desire for destruction and the end of literally everything.

It is self-aware and seemingly intelligent, knowing what it is doing and not caring at all.

On the other hand, the more human versions of Nyx, Ryoji Mochizuki, and Pharos have personalities.

Ryoji is surprisingly lively and exciting. He is similar to Junpei in a way, being flirtatious and a jokester at times. However, he is pretty kind and caring, but there is a depressing side to him in reality.

With Pharos, this is even more of a tragic and depressing side of Nyx. It is very little to his character besides the gloomy mood he constantly has. He is a pretty one-note kid, but there is a slight glimpse of kindness and love that is seen if you play the female protagonist.

Key Moments

Nyx Avatar is the final boss of Persona 3, so I think it is pretty clear that there will be lots of spoilers ahead. If you’re like me and like to head into a new game without any spoilers at all, beware of the next section.

The key moments and history of Nyx will inevitably spoil much of the main story of Persona 3.

Harbinger of the Fall

There is so much mystery surrounding the past of Nyx Avatar. We know through supplementary material that it is the Harbinger of the Fall.

However, how it came to have this status is essentially a mystery. I know that it is the Planet Eater alien from space, but its purpose beyond that is unknown.

From what we know, I can infer that it was probably a Planet Eater that went around destroying entire worlds and eliminating entire civilizations. It possibly arrived on Earth with the same purpose in mind.

At some point, though, it was not this Planet Eater but the god known as Death and Thanatos, which are the same.

It morphed into the Nyx Avatar after time but was ultimately prevented from destroying the world.

Unfortunately, Nyx Avatar was not defeated for good and, instead, became split into multiple different pieces. This was the birth of the Arcana that we all know so well in the Persona series.

The 14 different Arcana that make up Nyx and the main ones that we can connect with in the JRPG were all elements of it.

At the same time, Thanatos was another aspect of this creature. And there are still the humanoid versions of Nyx that formed in Ryoji Mochizuki and Pharos.

Stopping The Fall

At the beginning of Persona 3, players take on the role of the enigmatic male or female protagonist.

Within the dark and brooding world of Persona 3, players are quickly introduced to the prisoner boy Pharos. Not much is known about who or what he is, but he frequently appears to the player.

It is later revealed that Pharos is one aspect of Nyx. Another is Ryoji Mochizuki, who becomes a friend of the player.

His story is bizarre and fascinating as you befriend the main villain in the game. This is something that became an archetype in the series, but Ryoji remains one of the unique examples of this, in my opinion.

Along the way, Nyx attempts to bring about The Fall by sending out one of its split fragments every month.

However, it is unsuccessful each time as the SEES team of high school (after all, adults could never stop the end of the world) Persona users defeat each one every month.

This culminates with a significant decision that the player has to make. After mystifying myself and other players, Ryoji Mochizuki presents the truth to the player. He is an aspect of The Fall, and destroying him would put a stop to Nyx.

In the canon version of the story (honestly, you should never take the lousy route and kill Ryoji), the player chooses to keep Ryoji around.

Taking the easy way out is never the answer, and this was a test for the player. In this version, SEES continues its fight until the hour of The Fall.

Nyx Avatar awakens and returns in its complete form, awaiting the Tartarus tower’s top. It is here that the player engages with Nyx to determine the very fate of the world on a typical school night, no less.

The player and their team of party members successfully defeat Nyx Avatar after a very long and drawn-out fight.

After its defeat, though, Nyx Avatar reveals that it still intends to destroy all of existence, and the player faces it alone. The only way that the player can defeat Nyx is by sacrificing themselves.

After the fact, Nyx is defeated for good but can return in the story, either through subsequent playthroughs or Aigis’ epilogue story as Thanatos. We even see Elizabeth wielding Thanatos in Persona 4 Arena.

Nyx Persona 3 Boss Fight Explained

I know from firsthand experience that the Nyx Avatar final boss fight in Persona 3 is a doozy. Without a doubt, it is one of the most grueling final bosses in a game’s main story.

Sure, there are ultimate bosses in games, but they are usually optional for only the sickest masochists out there. However, Nyx is pretty much on that ultimate level while being a forced boss to finish the story.

Thankfully, I got your back. I beat this boss about ten years ago and am getting ready to face it again in my long-awaited second playthrough of Persona 3. I got your back with the tips and tricks so that you can survive this gauntlet through hell itself to stop the end of the world.

General Stats and Abilities

The most important part of this fight that I think you should bear in mind is that it has an unbelievable 14 phases.

Yes, you read that right. There are 14 phases to this fight, and it has to do with the fact that Nyx is bringing together the Arcana.

With this in mind, each phase is a different Arcana that you fight. The total health it has is 25,500, which is far above anything you’ve faced up until now.

However, that number is slightly bloated since it is divided between the 14 phases.

Each phase, minus the final one, which is the longest, has only 1500 health. That is a much more manageable number. Of the 14 stages, the first one is a throwaway since Nyx will do nothing the entire time.

I recommend just using regular attacks until this one is done, or else you are wasting your precious SP that you should save for the more critical other stages.

There are a few notable abilities that you should keep in mind for this fight. For starters, there is the problem that Nyx Avatar can attack twice per each of its turns.

This means that you are going to deal with, at the very least, two attacks or skills each time that it has a chance to fight.

This is worsened by the fact that it has some powerful skills that can deal devastating damage. But it is primarily a gauntlet of making your best attacks and healing up when necessary through each phase.

It is more of a grind than a super challenging fight, at least until the end. This is because it has no notable weaknesses or resistances, other than the fact that it is immune to light and dark, but that is unsurprising.

However, critical hits will only deal extra damage here and not grant a different turn, so keep that in mind. The general idea is simply to grind through each phase, taking your time and healing when necessary. Do not be afraid to waste an entire turn healing up.

Final Phase

The real challenge in the Nyx Avatar fight comes from the grand finale of it. Once you get through 13 phases, you will reach the last one.

Unlike the other phases, the Death Arcana phase has Nyx Avatar have a much more substantial 6000 health to it, compared to the relatively easy different steps.

There are a lot of problems that you have to worry about here, so I always recommend healing up as much as possible in the second-to-last phase of the fight to prepare for the onslaught that is about to happen.

The final stretch of the battle sees Nyx Avatar use some insane abilities like Night Queen.

This ability can charm your party members and spell the end of your boss’s battle run.

If charmed, your party members can attack one another, likely dealing some devastating damage at their high levels at this point, or, worse, heal the boss so that your hard work before is put to waste.

To counter this, I recommend getting any accessories and items that will prevent charm from happening in this final phase.

The other central part of the Death Arcana is the Moonless Gown attack. This skill has three parts to it, the first being nothing, the second being a charge, and the third being the actual attack itself.

Players should keep in mind that these three turns are wasted. You are unable to deal any damage whatsoever no matter what attack you use during these three turns.

This is the best chance to heal up your team and prepare for the insane attack that will happen. Guard on the final turn so that you take the least amount of damage possible.

Once Moonless Gown is over, unleash your best skills and try to take advantage of the window of time for attacking that you have until the next one is used.

Keep this rinse and repeat up, and you should be able to defeat Nyx Avatar in a few minutes. In total, though, this can be an insanely long fight that can be an hour or even an hour and a half for first-timers.

How to Summon Thanatos

The fruits of your labors come in the form of being able to summon one of the ultimate Personas in Persona 3: Thanatos. This is possible before the fight against Nyx Avatar and only requires you to have the max social link with Pharos first.

Once this is possible, it is recommended that you get Thanatos as it can, ironically, be one of the most useful Personas in the final fight.

To fuse for Thanatos, players must have several Personas beforehand. In the original Persona 3, this means fusing together Alice, Loa, Mot, Pale Rider, and Samael into one.

Some of them are extremely high level, so you will need to be at the required level to do this.

You will notice that those are all of the Personas that fit under the Death Arcana. Once you sacrifice all of them, you will be granted the Thanatos Persona through this extraordinary fusion.

Chances are, though, that you are not playing the original Persona 3 since that was never actually released in English. As such, there is an extra step that you must take.

A new Persona that appears in FES and Persona 3 Portable is Ghoul. You will need the above five Personas from the Death Arcana plus Ghoul, making a total of six, to summon Thanatos.

That added step is annoying but well worth it for one of the best Personas that you can use in the entire game, including The Answer epilogue.

Nyx in Other Games and Media

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Nyx Avatar is the final boss and is composed of many different forms. Atlus sure takes advantage of this fact, ensuring that it appears in many different places beyond Persona 3 and its plethora of game versions.

Even outside of the core JRPG itself, Nyx appears elsewhere.

It is present in the parent Shin Megami Tensei series, where it is vastly different and a much kinder version of the character that you can recruit.

There are also the official manga and anime film adaptations of Persona 3, where you can see Nyx Avatar in an even more horrifying fashion than the original game version. But, hey, at least it has incredible art.

Outside of Nyx, there is the Thanatos form of the boss. Thanatos appears in a lot of different games, including subsequent Persona titles as a recruitable Persona based on its Persona 3 appearance.

The most interesting of future appearances for Thanatos is Persona 4 Arena. Elizabeth, the Velvet Room assistant from 3, is a playable fighter in this game.

She wields Thanatos as her Persona, an exciting lore callback to her search for a way to free the protagonist.

Fun Facts About Nyx Avatar

Here are some fun facts about Nyx Avatar that you may not have known about before:

  • Starting with Nyx Avatar itself, the 14 phases of its boss fight have to do with the 14 Arcana that are present in Persona 3. Each phase that you fight in is against one of the Arcana incarnations.
  • Oddly enough, Nyx is not a spirit, demon, shadow, or standard Persona. Instead, it is an alien being from outer space known as the Planet Eater. This hints that it has perhaps destroyed worlds before.
  • Nyx is so vile and powerful that Fuuka, the team’s navigator, can sense its presence on her own without using her Persona.
  • Nyx appears in the Shin Megami Tensei series, though, hilariously enough, its appearance and style here are vastly different and far from the world-eating monster in Persona 3.
  • Ryoji Mochizuki has the same voice in both English and Japanese as the male protagonist of Persona 3.
  • This connection continues with the fact that his appearance is based on the male protagonist due to being one with him in the past. However, he does not change his appearance to look like the female MC for some reason.
  • Ryoji Mochizuki is confirmed to be bisexual, admitting in the female main character’s social link with him that he would like her if she was a guy or girl.
  • Pharos also has the same voice actor as Ryoji Mochizuki, his other self and the male protagonist in Persona 3.
  • Lastly, for Thanatos, its appearance in Persona 3 is far different from its previous look in Devil Summoner. This new appearance is seemingly based on the original descriptions of the god of death, Thanatos.


Question: What level should I be for Nyx Persona 3?

Answer: To answer this question, I think players should keep in mind that Nyx is level 76 when they face it at the end of Persona 3. With that in mind, I do not recommend that anyone tackle this boss without first being at least 75 themselves, if not 80 or higher.

Even then, it will be very tough. Some players can beat it at level 70, but those are the most experienced players who have done it before.

Question: How long does it take to beat Nyx Persona 3?

Answer: There are 14 phases to this fight, so you are looking for at least an hour to do this fight the first time, especially if you are not highly prepared. It can be much longer than that, though, even upwards of an hour and a half.

Question: Is Nyx an alien Persona 3?

Answer: While the main game does not make it clear, other material, including the official Persona 3 Club Book, reveals that Nyx is an alien that is known as the Planet Eater. There are also hints to this in some of Elizabeth’s story cutscenes in the Persona 4 Arena games.he first time or the first time in a long time, I’ve created a previous Persona 3 boss guide for every single one that you fight.


Nyx is the test of everything that came before in Persona 3. Every fight, shadow, and persona you encounter leads to the conclusion of the massive JRPG.

The biggest test for the SEES members, including the player’s protagonist, is taking on Nyx Avatar. Defeating it not only means saving the world but rolling credits on what I consider to be one of the best JRPGs ever made.

It is likely in my top five for the genre.

At the end of the day, though, this is but a single boss that players fight in Persona 3. There are still dozens upon dozens more major enemies that players fight within the calendar year that the game takes place.

Fortunately for players looking to tackle the game for t

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