Umbral Construct

The Umbral Constructs are wretched, monstrous creatures that wander Tetraverium. They are vestiges of darkness, that know only destruction and demise. They are trapped on the mortal plane, for not even death can reach them...

Origin

The origin of Umbra has been contested for centuries, and no true timeline has been formed around how it came to be. Some scholars would argue that Umbra first seeped into the world with the Great Sickness, when Teresa banished Sakuya, the Fey Spirit of Mt. Transcendence, into the darkness. Others trace it back to the Dragon Plague, and the birth of Iblis. Others still would argue that Umbra can be traced further back. An old legend tells of a King and Queen - the Invitors, who created Tetraverium out of spiritual mist. The King and Queen aimed to have children - but in the process, the Queen died. In his grief, the King descended into darkness to save her, only to discover the darkness had warped her. She had become an incarnation of death and decay. Forced to reconcile that they could never be together, the King fled the darkness, sealing her away. Whether or not this truly happened, it forms the basis of our understanding of Umbra. 
It is unclear whether or not the Gods knew of the Shadowfell's existence before or after the banishment of the Fragile Princess. Either way, with her banishment, an effort was made to derive purpose from it. The gods banished creatures they did not want into it's wretched depths. They created the Legislator's Asylum, and attempted to make it a bastion of order. However, every use of the dimension to suit their means would merely transform it further out of their control. Legends tell of how the gods' actions would lead to the formation of the Void Kings; Walpurgisnacht, the Rakshasa, and even the Shai'Tan. But did the gods create these entities, or did they already exist? 
The Shadowfell is a corruptive force - and over time, more and more of Tetraverium has been transformed by it. Landscapes, cultures, and technology have fallen victim to the unstoppable spread of darkness. But perhaps most crucial are the mortals themselves. With each mortal to tumble into darkness and become inundated with the cold, another has been transformed into something new. Not quite alive, not quite dead. Harbingers of the Void. These creatures are whispers in the night. A dreaded dark plague upon destiny and fate itself. They are Umbral Constructs - and the world does not have a place for them. 

Description

Umbral creatures come in all shapes and sizes. They are usually defined by a wretched, black ooze which consumes their forms. Some of them are more amorphous, able to warp and twist the shadow how they please. Others are more rigid, forced to confine themselves to a given form. Constructs do not age, and live forever. They can be almost any height, weight, or size. Their skin is often pale or dark colors. 

Socialization

The first reported sightings of Umbral Constructs came in Nerukudo, in the centuries after the Great Sickness. Families would report on the specters of those consumed by the darkness returning to them, tainted and corrupted by the hole which consumed them. They would attempt to reintegrate into their old lives, only to tear them apart. The Way of the Pure Soul would take shape around putting a stop to these Umbral incursions, creating shrines as bastions of spiritual power to cleanse the dead and force them back to whence they came. From there, sightings continued popping up: the animated corpses of dragons killed by the Dragon plague. Diseased corpses in Zinshali rising back up. And dreaded monsters hiding in the corner of your eye in Usheldom.
The world at large would not understand the true threat of Umbra until the rise of Walpurgisnacht and his Neverending Night. The Fallen Arbiter would attempt to bathe reality in darkness, rising out of Usheldom. Selestia was thrown under siege in an event that would warp the future of every nation that would come to rise there, including the Holy Kingdom of Du'Varn. Without the brave efforts of a small band of heroes, the world may not have survived. With this new, terrifying knowledge, the world set about limiting Umbra in all respects. The Forge Empire waged a war on wretched beasts and monsters. House Lavender was incorporated properly into the Gierelend hegemony due to their crystal's umbra-resistant properties. The world rallied against the darkness, but the darkness could not be stopped. 

Living in Tetraverium

In a way almost exclusively unique to them, Umbral Constructs do not "live" in Tetraverium. Even the Hellspawn, hunted back to their home plane, have managed to integrate into the world better than creatures that are destined to never inhabit this realm. To be an Umbral Construct is to be hated, reviled, and hunted. Few understand what they are, and those that do know just how dangerous they are. 
Most constructs will relegate themselves to the Shadowfell, accepting their lot in life. While more welcoming to the Umbral Constructs, the Shadowfell is not a place where life thrives. Instead, it is a realm designed almost in opposition to life. Within the realm of order, everything is forced to conform to a rigid hiearchy. Those that do not wish to conform do not have the power or means to escape their fate. Every organism within the Shadowfell is linked, and can sense one another through a complex web of emotion and pain. Societies in the Shadowfell are built upon either preservation or war. Some prepare to fight other constructs within other realms, to gain power for their Void King. Others flee to the edges of the world, hoping to avoid being drafted into an eternal war. 
Umbral Constructs are rarely understood in most nations, and usually roped in with other monsters and beasts. If one is encountered, you can count on the Pale Knights or Inquisitors to not be far behind. There are two nations that harbor a slightly greater understanding of these creatures: Nerukudo and Usheldom. These industrial capitals have encountered constructs in the remains of their innovation. In Nerukudo, Umbra is feared and reviled as a part of the Way of the Pure Soul. They are cleansed and dispatched in any way possible. However, as their culture has industrialized, some have come to accept Umbral Constructs. In Usheldom, Umbra is accepted as a consequence of their technology. Though still reviled, Umbral creatures can often form a home in the frigid wastes. 

Subraces

There are four Umbral subraces: Pure, Bestial, Forgotten and War. Each is linked to the domian of one of the four major Void Kings: the Fragile Princess, the Unceasing Hunger, the Neverending Night, and the Deafening Whisper.

WARNING

This is a powerful species with mechanics that may be beyond some campaigns run in Tetraverium. Ask your DM before creating an Umbral Construct if the species is available to be used in your upcoming campaign.

Mechanics

When you choose Umbral Construct as your species, you gain the following benefits:

Ability Score Increase: You can increase one Ability Score by 2 and another Ability Score by 1.
Creature Type: You are an Undead. This does NOT prevent you from being afflicted by healing magic.
Size: You are Large, Medium or Small. You choose the size when you select this race.
Speed: Your walking speed is 30 feet.
Darkvision. You have Darkvision out to 60 ft.
Beyond Death. You gain the following effects as a construct of darkness: 

You don’t need to eat, drink, or breathe.

You are immune to disease.

You don't need to sleep, and magic can't put you to sleep

You have disadvantage on Death Saving Throws. 

When you die, you enter a state of umbral reconstruction. After 1d4+1 hours have passed, you can come back to life as a Free Action. You regain 1 hit point and fall prone. Once you have used this ability, you cannot use it again until the next dawn.

Tamed by Darkness. You gain proficiency in one of the following skills of your choice: Acrobatics, Deception, Intimidation, Stealth, or Survival
Wretched Nature. You have resistance to Necrotic Damage.
Languages. Your character can speak, read, and write Common and Abyssal.
Subrace.When you choose this species, choose one of the following subraces:

Pure Construct

Shapechanger. You can cast the Disguise Self without expending a Spell Slot. Starting at 3rd Level, you can cast the Alter Self spell without expending a spell slot. Once you use these spells in this way, you can also cast them using your existing spell slots.

Bestial Construct

Apex Form. As an Action, you can enter a monstrous form for 10 minutes. While in this form, you gain advantage on Survival Checks intended to track creatures, your Movement Speed increases by 10 ft, and your Armor Class increases by 2. Additionally, all of your weapon attacks gain the "Topple" property in addition to their existing properties.
When you use this transformation, you must finish a Long Rest before you can use it again. When you reach 11th level, your Armor Class increases by 4 and your movement speed increases by 20 ft.

Forgotten Construct

Void Strike. You are difficult for others to remember, making it easier to land an attack on unsuspecting foes. When you make an Attack Roll, you can give yourself advantage. If the attack hits, it deals an extra 1d8 necrotic damage. This damage increases to 2d8 at Level 6, 3d8 at Level 11, and 4d8 at Level 16.
Once used, you cannot use this ability again until you finish a Long Rest. Alternatively, the DM can choose to have a relevant NPC forget who you are in a way that sabotages your progress. If this occurs, you immediately regain your expended use of Void Strike.

War Construct

Vessel of Whispers. You can accurately mimic sounds you have heard, including voices. A creature that hears the sounds you make can tell they are imitations only with a successful Wisdom (Insight) check against a DC of 8 + your proficiency bonus + your Intelligence, Wisdom, or Charisma modifier (choose when you select this subrace).
You can use your whispers to drive creatures to war. As a Bonus Action, you can deliver a Whisper to a creature that can hear you within 60 ft. It must make a Wisdom Saving Throw against your Mimicry DC. On a failure, it must use its Action on its next turn to make a Weapon attack against the closest creature. Once you use your whispers in this way, you cannot use it again until you finish a long rest. Starting from 11th level and onward, you can use this trait twice per Long Rest.