Introduction

The concept of nothingness has always fascinated human nature. The impossibility to visualize it captivates us — and just when you think you have managed to make it fit in your mind, you realize it's pointless. This guide will provide NPCs that have made that fascination their life, monsters that are this very concept incarnate, and player options for those that wish to create a character that traverses those unimaginable lines.

This document is structured in an unusual way. Instead of always giving concrete facts, it will sometimes provide possibilities meant to stimulate your own imagination, leading you to find your own answers. This is to ensure that this content can be applied to any world and any context, and that the ideas contained within can be picked and chosen, as well as be developed into their own thing. To further support this effort, the chapters of this guide have been structured in order of their creation, instead of a more 'logical' way.

The first chapter concerns Dark Essences, abnormal elemental creatures that have been created, instead of summoned, by dark conjurers that seek to do the unthinkable. The Dark Essence is usually as far as most of them have gotten in their search of a Null Elemental.

This creature, for example, has been put first — in place of other more central topics — in order to stimulate your own imagination and lead you to create a story in your mind. As the denizens of this world would first come to know Dark Essences, so can the reader, before approaching what hides behind the minds of the mages that created them. Each chapter of this guide can lead to any other, so you can connect them in any way you like, and hopefully the gaps between them will inspire you to create your own creative tissue between them.

Dark Essence

Dark Essences are abnormal elementals, the result of a dark conjurer's attempt to bring nothingness into being. Most conjurers spell their own ending in such attempts, but there exist a few talented individuals known for being able to create them and control them.

These elementals are the closest thing the dark conjurers of Festung have come up with in their search to create a null elemental, a being that is the pinnacle of chaos and nothingness, and defies all rational knowledge simply by existing.

Few have realized that because of the dark essence's natural affinity towards the negative plane, and its hollow fabricated existence, it can be a vessel for dark extraplanar forces to occupy and inhabit. Incorporeal forces that lie at the end of the astral sea and cannot manage to bring themselves into corporeal existence.

They are able to look into the material realm for the first time through these dark essences, and usually prefer to bide their time having not known of its existence before. They continue to silently observe in order to understand the newfound concepts of physics and corporeal matters before they inevitably begin to extend their influence into the material realm.

Null Elemental

Null elementals break the very fabric of existence by existing. Whether its creation was accidental or intended, an event of great concentrated energy would have taken place that would have ripped open the fabric of spacetime. Such beings — though that word complicates matter, as many wizards will tell you — have been theorized for centuries. Many mages have recklessly attempted to prove their possibility of existence, either for the pride in recklessly achieving the unachievable, foolish and overconfident intentions of controlling one, or bringing limitless nihilistic destruction to the material realm.

Null cults have sprung up throughout the centuries that worship the concept of absolute nothingness, proving the absurd human fascination with matters beyond comprehension. Time and time again these cults have attempted to bring a null elemental into existence by recruiting wizards of great power and infecting them with this absurd fascination, blackmailing them, or searching for timeless relics of arcane power that could be a potent enough power source to punch a hole in the universe.

No null elemental has ever been successfully created, at least as far as anyone can know. The existence of one would disrupt the entire material plane, but arcanists threorize that if one was somehow created, corporeal beings would have no way telling the difference until it arrived right in front of them to wipe them from the face of existence. And only those of a strong enough mind would have the capability of perceiving the null elemental as it pulled their molecules back into nothingness. Creatures and objects destroyed by a null elemental would be wiped from existence — present, past and future — so that even if a null elemental has wiped out a whole continent, no one would be able to remember that continent existing.

Some cults preach that this is already happening, and at any living moment of a creature, its eventual demise is perpetually approaching. Some equally insane cults believe that this is the only true aspect of existence. Matter is only made so that it can be unmade in this way, and one should come to terms with the invisible ending always approaching by this ultimately natural force. Others believe that this demise has already occured time and time again in previous universes. That it is the unavoidable purpose of humanity to tamper with that which they don't understand, until they cause their literal undoing. Timeless eons would pass until a new universe was born, and it would play out the same way once again, creating an incomprehensible loop of existence and nonexistence tied together by their very definitions.

Null Life. The null elemental is comprised of nothingness, and turns anything it comes in contact with to nothing. Thereby, it cannot be destroyed in conventional ways. However, if the null elemental is exposed to enough raw energy in a short enough period of time, it will reach its destabilization threshold, which can be exploited in order to contain it using the Convergence Pylons. See 'The Quest to Remake the World' below.

Destabilized Form. If the null elemental takes enough damage to reach its destabilization threshold in 1 minute , it becomes destabilized for 1d8 days. For the duration, any creature that starts its turn within 30 feet of the null elemental must make a DC 21 Constitution saving throw, taking 30 nulling damage on a failure, or half as much damage on a success. In addition, at the start of each of its turns the null elemental teleports to a random point within 120 ft. of it. Roll 1d8 to determine the direction, and 1d12 (x10) to determine the distance the elemental teleports.

Nulling Damage. The null elemental does not abide by the rules of physics or the elements. The damage it deals ignores all regular resistances and immunities, as it returns all creatures and objects alike to nothing. As such, this type of damage is described as nulling, in order to prevent interactions with other damage type resistances. Even if a creature has resistance or immunity to all damage, it does not have resistance or immunity to nulling damage unless explicitly stated.

Null and Void. The null elemental can occupy an area of 40 cubic feet, and can occupy the same space as creatures and objects. When the null elemental enters the area of a creature or object, the target must make a DC 21 Dexterity saving throw, taking 27 (6d8) nulling damage on a failure, or half as much damage on a success. On a success, the creature rolls away out of the path of the null elemental, moving to the nearest space that isn't occupied by the elemental.

If a creature starts or ends its turn within the space of the elemental, or hits it with an attack while within 10 feet of it, it must make a DC 21 Dexterity saving throw, taking 27 (6d8) nulling damage on a failure, or half as much damage on a success. A creature can only take this damage twice per turn.

Destroyer of Matter. The null elemental deals 4 times as much damage to objects and structures. When the null elemental reduces a creature or object to 0 hitpoints, the target is absorbed into the null elemental, and its body is returned to nothingness.

Actions

Multiattack. The null elemental makes three nullifying strike attacks. It can substitute up to 2 of nullifying strike attacks for a nullifying bolt attack.

Nullifying Strike. Melee Weapon Attack: +19, Reach: 10 ft., one target. Hit: 28 (4d8+10) nulling damage.

Nullifying Bolt. Ranged Weapon Attack: +19, Range: 120 ft., one target. Hit: 28 (4d8+10) nulling damage, and the target must succeed on a DC 21 Constitution or Charisma saving throw (the target's choice), or be unable to cast any spells until the end of its next turn. Nullifying Pulse (Recharge 6). The null elemental releases a pulse of negative energy. Each creature within the space of the elemental and within 10 feet of it must make a DC 27 Constitution saving throw (if they are inside the space of the elemental) or a DC 27 Dexterity saving throw (if they are within 10 feet of it). On a failure, a creature takes 81 (18d8) nulling damage and is slowed for 1 minute as per the slow spell. On a success, a creature takes half as much damage, and is only slowed until the end of its next turn. If a creature dies from this damage, the null elemental expands, becoming 5 feet larger in each of its dimensions.

Legendary Actions

The Null Elemental can take 5 legendary actions, choosing from the options below. Only one legendary option can be used at a time and only at the end of another creature's turn. The Null Elemental regains spent legendary actions at the start of its turn.

Move. The elemental moves up to its movement speed.

Nullifying Strike. The elemental makes a nullifying strike attack. On a hit, the creature must succeed on a DC 21 Wisdom saving throw or it is slowed for 1 minute as per the slow spell. The creature can repeat its saving throw at the end of each of its turns, ending the effect on itself on a success.

Existential Siphon (Costs 3 Actions). If the null elemental has reduced a creature to 0 hitpoints since its last turn, it can reach through the 4 dimensions and siphon as much matter as it can into oblivion. Parts of it appear out of the ground at random areas around it. Any creatures within 30 feet of the elemental must make a DC 21 Charisma saving throw. On a failure, roll 1d4 for each creature that failed its saving throw.

d4	Result
1	One of the limbs of the creature phases out, becoming permanently lost
2	The creature falls to 0 hitpoints.
3	The creature can't regain hitpoints ever again.
4	The creature is shunted into an alternate dimension

The Quest to Remake the World

Most of the theories regarding null elementals are largely speculations based on what can be theoretically surmised about their nature. A number of theories contradict each other, while the rest fight over the issue of whether a null elemental is even possible to exist in the first place.

When the null elemental first appears, its arrival will be followed by great turmoil and death as champions of the continent of Sul throw themselves at it without result. Little will be evident to the rest of the world of the great destruction that has befell the continent, as the memories of the perished fade from the timeline as quickly as their lives. Only a faction of the esoteric wizards of Sibil (an old city a continent across) will be clued in to what has possibly happened, as some of their data gathering instruments are showing abnormal fluctuations in the middle of a vast empty ocean. When ships from Sul begin arriving at the ports of Sibil without anyone remembering their place of origin, the clues will start to be put together, and dusty tomes discussing null elementals will surface once again.

The wizards of Sibil will need to organize expeditions closer to the eye of the tornado in order to conduct readings and begin working on a solution. The player characters could be part of that multi-legged expedition, as they struggle to determine what it is the world is up against, and what can be done about it. They will need to quest in order to figure out how to remove the null elemental from existence and how to protect themselves from annihilation while doing so, as it will become clear quite early that traditional methods of just blowing your enemies to pieces will not be effective here.

This expedition could lead to the construction of items meant to combat some of the elemental's abilities, finding ways to become resistant to nulling damage, finding a way to protect oneself from being erased out of existence by it, and even how to perform the ritual that would be necessary to seal it away or banish it.

Illivar's Theorem

There is only one way of combating such a cosmic dimensional threat: cosmic dimensional experiments. Feliden Illivar was an elf known for his absurd theories on multiple dimensions, alternate realities, and spacetime. And even more so for his lack of social inhibitions and disregard of arcane safety regulations. Getting to 1000 years old as an elf will do that to you. Or so they say. No other elf has lived that long.

While dusting the tomes in search of finding possible avenues of attack against the elemental, a report on Illivar's proposal to build a huge arcane barrier around the city of Sibil was discovered. Six hundred years ago, Illivar was looking to put to practice his half concocted theories about building a crossdimensional barrier through which absolutely nothing could pass through. He proposed it as a way of enhancing the defenses of the city in an attempt to gain the funding that he needed to pursue his interests, but was flatly rejected. The report noted that Illivar's proposal had been deemed outlandishly expensive, purposefully impractical, and wildly unpredictable. All because fundamentally, Illivar was looking to test his abstract theories rather than build something of use.

That outlandish Convergence barrier that interacts with the very fabric of space — dissecting it — seems like the closest thing in existence that could stop the null elemental. Except that it doesn't exist. Illivar had never gotten the opportunity to develop that particular theory and had quickly hopped from obsession to obsession afterwards, never looking back.

Now, the city of Sibil, along with every other city state of the continent have put off their rivalries and banded together in order to engage the threat of the elemental. Finding Illivar is of the outmost priority, but someone will need to be sent to investigate in search of him. He hasn't been seen in the last 50 years. And rumour has it he vanished in his last laboratory, while he was experimenting on his theories regarding alternate dimensions...

After the players manage to piece together the notes of whatever is left in illivar's old lab, they can attempt their impromptu version of the "Dream of the Blue Veil" incantation he had crafted. The goal will be to locate Illivar if he is alive, get him back to our reality and make sure he has everything he needs in order to finish that barrier.

After the barrier's development is complete, its practical application will need to follow. Illivar is certain that for this to work, the elemental will need to be in its Destabilized Form, otherwise it will just eat through the pylons that will be employed for its activation. The player characters will need to fight the elemental long enough for it to enter that state, and also make sure they wont be dead by then because the Convergence Pylons will need to be planted in the correct positions around it, and activated on site.

How Many Steps of the Journey?

Depending on how long you'd like to make the campaign, as well as the starting level you'd like to consider, you can employ different plotlines for your version of this adventure. For example, the player characters could be the ones that first discover something is going wrong with the continent of Sul. Perhaps one of the characters is a wizard that has received strange readings, or a sailor that arrived at port after a really long journey with no idea of where they came from.

• The first expedition (to investigate the threat) could be made to be an entire arc, as there will definitely be complications to the journey, hard decisions to make, and people to save and make your allies. Getting to be close to the elemental without ever actually fighting it — because you know you'll simply be annihilated will highlight the deadliness of the threat. Proponents of the Null Cults could surface throughout the whole world, trying to thwart the expedition and throwing the whole world into even more disarray. And perhaps they're more central to the story than they seem. Maybe a cult's leader has access to items and old relics that will be very important down the line. Perhaps if the players choose to deal more with them, you will have a chance to reveal how the elemental came to created in the first place.

• For a political arc, the party could be the ones that make sure the world knows of the issues. Most likely, the different political factions in the area will need convincing. They won't just take doomsday prophesies for granted, so they'll need proof in order to lend their necessary support (perhaps they have capabilities of finding Illivar, or possess a unique metal that will be necessary for the creation of the pylons). All the while, the Princes of Sanar has found this to be the perfect time to conduct their schemes and ploys in order to exploit the situation to their political benefit — and likely to the destruction of the whole world.

• For an arc around scientific investigation, the attempt of the players to recreate Illivar's experiments could prove to be its very own challenge. Perhaps parts of the lab have been raided in the last few years and key components are missing. Who took them? Perhaps the Planar Watchers, an organization that knows about the alternate realities that exist and closely guards the borders between universes has learned about Illivar's achievement (more like accident) and has decided not to let any other irresponsible individuals slip past their watchful eye. If the wrong person crossed the borders, even interplanar war could break out.

• Lastly the reality hopping adventure could have as many subplots as needed, in order to make every place the players visit feel unique and have its own character, rather than being a placeholder for "Place 1". After all, who knows what Illivar has gotten to after disappearing, and what he's gotten himself mixed up with. He's likely to have made both friends and enemies (okay maybe enemies a bit more).

At any point during these stages the characters could have opportunities to gather resources, materials and knowledge needed to craft powerful anti-null magical items. This adventure is recommended for levels 15 and upwards. The party will definitely need to be level 20 (or more) when they face their last challenge.

The list of arcs and subplots listed above is anything but mandatory. You can decide what happens on the foreground, and what the NPCs take care of in the background. Assess your players' interests (or merely let them choose for themselves) and plan accordingly. It should also be noted that it is not a good idea to stuff a narrative with dozens of plotlines and sidestops just because you can, and they're there. Do whatever is most suitable for the pacing your table will have. This adventure could take a year, but it could also take 4 sessions.

In the following sections you will find the statblock for Navilid, an exiled mind flayer who experimented with null elementalism, and was ostracized for it by his colony. He may or may not be responsible for the minor issues that came to plague the world as described above. Additionally, you'll find player options such races, items, and subclasses, including the Null Elemental Patron for a warlock that should probably change patrons.

Navilid, the Mind Flayer Elementalist

Navilid, even as a young ilithid, was fascinated by space. He would stare at the stars for hours — unblinkingly — trying to let his mind comprehend the vast distances he was observing. To be fair, all of the mind flayers had an interest in space. But his was different. Where the others thought as one with the Elder Brain and planned the expansion and well-being of the colony, he preferred to be consumed by his star-gazing thoughts alone. And when others viewed the stars as destinations — homes for worlds to conquer — he saw them as travelers, unerringly making their way through the heavens, ever so slowly. He imagined how populated some could be, and how sparse and dead others were. And yet they all looked the same from so afar. So small.

He couldn't look away when he learned that some of the stars he was gazing at were already dead. Behind the veil of the slow-travelling light now he knew secretly stood a void. And who knew how many more of the stars where the same. How much of the universe was secretly quiet? A quiet and peaceful void, everlasting and yet everchanging. The remnants of the star traveling alone for some reason brought him peace. His eyes failed to see it just as the eyes of the others did. There was light after all. Everything was fine. But in his mind he could see it. And he found it intoxicating — the power behind all of reality — hiding from everyone.

He imagined the quiet again. He could exist in it without bothering it, and without it bothering him. It he could be one with it, that peaceful quiet would make him feel whole. It would be his natural state. And he would finally find something with which he could think as one.

The other mind flayers severed him from his tentacles for meddling with null elementalism — the worst form of arcanism — and exiled him away and alone. But that did not matter.

Navilid

Medium aberration, any alignment

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• Armor Class 16 (Nullsmoke breastplate)
• Hit Points 71 (13d8 + 13)
• Speed 30 ft.

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STR	DEX	CON	INT	WIS	CHA
11 (+0)	12 (+1)	13 (+1)	19 (+4)	17 (+3)	17 (+3)

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• Saving Throws Int +8, Wis +7, Cha +7
• Skills Arcana +10, Deception +6, Insight +6, Perception +6, Persuasion +6, Stealth +4
• Senses darkvision 120 ft., passive Perception 16
• Languages Deep Speech, Undercommon, telepathy 120 ft.
• Challenge 11 (3,900 XP)

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Innate Spellcasting (Psionics). The mind flayer's innate spellcasting ability is Charisma (spell save DC 15). It can innately cast the following spells, requiring no components:

At will: misty step, dispel magic

1/day each: synaptic static, plane shift (self only)

Magic Resistance. The mind flayer has advantage on saving throws against spells and other magical effects.

Nullsmoke Breastplate. Navilid has enchanted his breastplate with the power of the void. He has resistance to nulling damage. Any creature that hits him with an attack while within 5 feet of him takes 4 (1d8) nulling damage.

Spellcasting. The mind flayer is a 10th-level spellcaster. Its spellcasting ability is Charisma (save DC 15, +7 to hit with spell attacks). The mind flayer has the following spells prepared and can cast them without requiring any components:

1st level (4 slots): absorb elements**, chaos bolt, thunderwave, shield

2nd level (3 slots): silence, moonbeam, nullifying smite*

3rd level (3 slots): blink, counterspell, pulse wave, slow

4th level (3 slots): summon dark essence*, shadow of moil, wall of void*

5th level (2 slots): temporal shunt, wall of force

*These custom spells are detailed in the next page. Navilid can cast nullifying smite without requiring concentration. When he does so, the spell has a duration of 1 round.

** Can also be used against force and radiant damage

Actions

Multiattack. Navilid makes two null blade attacks.

Null Blade. Melee Weapon Attack: +7, Reach: 5 ft., one target. Hit: 20 (3d10 + 4) nulling damage.

Mind Blast (Recharge 5–6). The mind flayer magically emits psychic energy in a 60-foot cone. Each creature in that area must succeed on a DC 15 Intelligence saving throw or take 22 (4d8 + 4) psychic damage and be stunned for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Legendary Actions

Navilid can take 3 legendary actions, choosing from the options below. Only one legendary option can be used at a time and only at the end of another creature's turn. Navilid regains spent legendary actions at the start of its turn.

Teleport. Navilid casts misty step.

Null Blade. Navilid makes a null blade attack.

Psychic Drain (Costs 2 Actions). Navilid leeches on the mental energy of a creature within 60 feet of it. The target must succeed on a DC 15 Intelligence saving throw, or take 16 (3d10) psychic damage, and Navilid gains a number of temporary hitpoints equal to the damage dealt. On a successful saving throw, the target takes half as much damage.

Spells

The following spells utilize the power of the void to create nullifying effects. You can give your players access to these spells at your discretion, if the narrative calls for it.

Summon Dark Essence uses the 4th level spell summon elemental for its mechanics, but summons a dark essence instead of an elemental spirit. This spell is designed to be only used by Navilid or similar NPCs, as it increases its power significantly. (If you would like your players to be able to summon a dark essence, consider making this spell 6th or 7th level for them, or giving them a bead of dark essence as loot)

Items

The Void

Your inexplicable powers come from the vast, endless expanse of space, incomprehensible in its inhumanity, and grander than anything a humanoid could ever fit in its mind. This link between you and it might have been created in various ways.

Some sentient creatures are more sensitive to the underlying methods of the cosmos, and find the concept of inexistence just as beautiful as existence. It is always there, by necessity of definition, and you felt a kinship with it when you were looking up at an empty patch in an otherwise starry night. This kinship could have either allowed you to form an innate connection to the void, thus drawing power from it, or you decided to study and research it, thus coming across obscure knowledge that opened new vistas of reality to you — and new capabilities.

On the other hand, if you'd like your patron to be a conscious creature rather than a force of nature, your patron could be an individual — such as Navilid — that has uncovered great knowledge about the void, has put that knowledge into practice. They have come to be in tune enough with the void that they can bestow that power into others as well, and have selected you as their protege — or perhaps just another minion. What will you think of their agenda and their plans? Do they line up with how you see the world, and the force behind both your powers? Will you follow their cause, or create your own path?

Invocations

At 2nd level, a warlock gains the Eldritch Invocations feature. Here are new options for that feature, in addition to the options in the Player's Handbook.

If an eldritch invocation has a prerequisite, you must meet it to learn the invocation. You can learn the invocation at the same time that you meet its prerequisite. A level prerequisite refers to your level in this class.

New Familiar

The nullifier is a new choice of familiar for warlocks of the Void with the Pact of the Chain feature. The nullifier is a small elemental made of null energy that a warlock attuned with the Void can bring into existence.

Nullborn

When a null elemental first comes into existence, complete destruction in its near vicinity is not the only effect observed. Throughout the whole plane, no matter the distance from the elemental, disruptions in the laws of physics are observed now and then. Besides miniscule changes in gravity and the flow of time, some creatures produce offspring that is touched by the errant energies dispersed by the multi-dimensional creature.

These people at first appear to phase in and out of existence the more you look at them. Once a person matures, it begins to learn to stabilize itself, however a blue unearthly glow is always surrounding their physical body. Nullborn don't need to eat, drink or breathe, which sets them apart in the communities they're born in. While others sleep, nullborn need to meditate on their existence, grounding it into reality and prevent it from slipping away into nothing. Rumor has it that a nullborn that reaches perfection in their talent could sustain themselves in existence forever, but some nullborn never learn to master it, phasing out of existence only a few years into childhood.