Huge fiend (demon), Chaotic evil
Armour Class: 19
Hit Points: 150 (12d12 + 72)
Speed: 0 feet, fly 20 feet (hover)
Saving Throws: Intelligence +13, Charisma +13
Skills: Arcana +13, History +13, Perception +13
Damage Resistances: cold, fire, lightning; bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities: Poison
Condition Immunities: Poisoned
Senses: Truesight 120 feet, Passive Perception 23
Languages: All, telepathy 120 feet
Contamination. The sibriex emits an aura of corruption 30 feet in every direction. Plants that aren’t creatures wither in the aura, and the ground in it is difficult terrain for other creatures. Any creature that starts its turn in the aura must succeed on a DC 20 Constitution saving throw or take 14 (4d6) poison damage. A creature that succeeds on the save is immune to this sibriex’s Contamination for 24 hours.
Innate Spellcasting. The sibriex’s innate spellcasting ability is Charisma (spell save DC 21). It can innately cast the following spells, requiring no material components:
At will: charm person, command, dispel magic, hold monster
Legendary Resistance (3/Day). If the sibriex fails a saving throw, it can choose to succeed instead.
Magic Resistance. The sibriex has advantage on saving throws against spells and other magical effects.
Multiattack. The sibriex uses Squirt Bile once and makes three attacks using its chain, bite, or both.
Chain. Melee Weapon Attack: +6 to hit, reach 15 ft., one target. Hit: 20 (2d12 + 7) piercing damage.
Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 9 (2d8) piercing damage plus 9 (2d8) acid damage.
Squirt Bile. The sibriex targets one creature it can see within 120 feet of it. The target must succeed on a DC 20 Dexterity saving throw or take 35 (10d6) acid damage.
Warp Creature. The sibriex targets up to three creatures it can see within 120 feet of it. Each target must make a DC 20 Constitution saving throw. On a successful save, a creature becomes immune to this sibriex’s Warp Creature. On a failed save, the target is poisoned, which causes it to also gain 1 level of exhaustion. While poisoned in this way, the target must repeat the saving throw at the start of each of its turns. Three successful saves against the poison end it, and ending the poison removes any levels of exhaustion caused by it. Each failed save causes the target to suffer another level of exhaustion. Once the target reaches 6 levels of exhaustion, it dies and instantly transforms into a living abyssal wretch under the sibriex’s control. The transformation of the body can be undone only by a wish spell.
The sibriex can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn.
The sibriex regains spent legendary actions at the start of its turn. Cast a Spell. The sibriex casts a spell. Spray Bile. The sibriex uses Squirt Bile. Warp (Costs 2 Actions). The sibriex uses Warp Creature
What is a Sibirex?
The Sibirex is undoubtedly one of the Forgotten Realms’ most horrifying creatures. These Obyrith demons grafted Abyssal flesh to their timeless bodies until they became naught more than floating, head-like masses of rotting flesh.
These demons, though hideous, are not unintelligent and are masters of the Arcane and the magicks of old.
The Obyriths are an Eldritch demon race that predates mortal life. Even before becoming Sibirex, the Obyriths were not only ugly but outright wrong. Even the cosmos itself rejected these fiends.
The Obyriths of old featured many distinct varieties, each as alien as the one before it, bearing no resemblance to modern mortals.
The Obyriths were horrifying in every aspect of their existence. From the sounds they made to the scents they carried were vile in every sense of the word. Until the Tana’ri nearly wiped them out, the Obyriths were a dominant race of demons in the Abyss.
The Sibirexes were Obyriths who could manipulate flesh. They viewed skin grafting as an art and viewed other demons as mere material for grafting and experimentation.
The exact thought processes of a Sibirex remain unknown, even to well-studied demonologists. What we do know is that the Sibirexes were violent and callous.
They were bullies who enjoyed tormenting any weaker creatures but avoided anything stronger or more intelligent than themselves.
Their Mens rea is to improve and increase their own power. They care not for politics or friendship, only brute force, and power. Their vast knowledge leads them to a vain and arrogant mindset.
Any creature which successfully barters with them for their assistance can expect to pay an exorbitant fee of goods and services for the Sibirex’s time.
One might pay a Sibirex in gold, art, or magic items and weaponry with which the Sibirex will decorate their lair. They’ll keep many magical things and weaponry to gift to their favorite servants even if they can’t use them personally.
These gifts are intended to help said servant carry out tasks for the Sibirex and will generally be related to their servant’s duties.
The Sibirex is so horrifying to see that the mere sight of one can drive someone insane. They were able to warp the minds of other creatures with their Eldritch powers.
Twisted creatures would start to view the Sibirex as the perfect lifeform, which they would serve until they drew their last breath. By focusing their energy, Sibirexes could instantly warp several nearby creatures at once and turn them into Abyssal wretches.
Once turned by a Sibirex, the only way to regain their former visage was a Wish spell.
A Player’s Guide to Hunting Sibirexes
Sibirexes are a frightening enemy that packs quite a punch for the uninitiated. Low Constitution players will want to stay as far away from the Sibirex as they can to avoid even being targeted by Warp Creature.
Warp Creature leaves your character vulnerable to death from the posion and vulnerable to becoming a turncoat under the Sibirex’s control.
The Sibirex packs a lot of damage, not even relating to the Warp Creature ability. The Warp Creature ability is kind of just the icing on the carrion-cake, so to speak.
Bringing not just magical resistance but legendary resistance and actions makes the Sibirex a devasting threat to parties who aren’t prepared to take on the Sibirex’s violent nature.
You’ll want a beefy frontline who can stand up to the Sibirex’s Warp Creature ability. This frontline can attract the Sibirex’s attention to its immediate threats and help keep the squishier, ranged characters safe in doing so.
Those who can cast Lesser Restoration will want to hold spell slots for the spell in case Warp Creature poisons anyone.
Spellcasters will want to focus their efforts on damage outside of Cold, Fire, and Lightning. So, unfortunately, no Firebolts or Fireballs, but spells like Toll the Dead, Inflict Wounds, and Thunderwave will allow you to deal large amounts and deal full damage while doing so.
A Dungeon Master’s Guide to Sibirexes
Dungeon Masters who want to include Sibirexes in their campaigns will want to remember that while the Sibirex is hideous and unsightly, it is not unintelligent.
These creatures are ancient Eldritch abominations that bear profound knowledge of the arcane, not mindless, violent beasts.
Sibirexes are also not unwilling to reason with other creatures. While they may lack empathy for their situations, they are not incapable of reason. A player who can offer adequate compensation may find that a Sibirex is more than willing to trade secrets and lore for coin.
Some Sibirex even act as advisors and oracles for demonkind, sharing their knowledge with their servants. Others will hoard knowledge like dragons, doling out information only when it suits them.
Given the amount of power that Sibirex has, it wouldn’t be unreasonable for such a creature to have some Warlocks. It would be unlikely that you would have a lone Sibirex rather than one being flanked by its servants who will die without question to protect it.
Sibirexes are a terrifying and excellent addition to any campaign. Whether they serve as a greater evil for the players to overcome or a disturbing advisor to help them on their adventures, the Sibirex’s profound knowledge can play a decisive role in any storyline.