Void Shadow

"There was a shadow on the rooftop behind Daud, peeling out of the darkness, its form indistinct, its claw-like arms stretching out, impossibly long, reaching for Daud."

- Billie Lurk seeing the Void Shadow for the first time.

Void Shadow is a supernatural creature and an antagonist in Dishonored: The Veiled Terror.

Characteristics
The Void Shadow is a creature made up of black, shifting mass of smoke and darkness, with an oval head and two dark spots for eyes. It has a strange, elongated body, with long arms end with blade-like fingers and voice sounds like howling wind. Within the opaque, smoke-like body, there is a physical form, which is its weak point. When this physical form is injured, a inky black liquid comes out - the closest thing it has to blood.

The Void Shadow has many different abilities which makes the creature very deadly. It possesses a limited shape-shifting capability, such as shifting its body mass to strengthen certain body parts, or lengthen and sharpen its claws. The smoke coming out of its body can act as a defense mechanism, burning eyes and noses of whoever comes too close. It can crawl on walls and ceilings at will, and is very fast, able to kill multiple targets with blinding speed. The creature also has a movement ability that transforms itself into a small tornado of dust and shadow, moves swiftly, and materializes elsewhere to strike at unsuspecting targets. What makes the Void Shadow truly dangerous, however, is its ability to open void rifts and travel to any given timeline.

The Veiled Terror
Billie Lurk encountered the Void Shadow for the first time while she was infiltrating the House of the Fourth Chair, the winter palace of King Briam and Queen Eithne of Morley. She followed the creature through different void rifts and witnessed its attempts to alter significant events in history.

The first void rift transported Billie back in time, to the moment when her teenage-self first saw Daud. Daud, instead of assassinating the three guardsmen, was attacked by the Void Shadow. The creature was so strong it managed to overpower a supernaturally enhanced Daud and would have killed him if it hasn't been for Billie's intervention. The assassin then blinked away and escaped, while the teenage-Billie, witnessing the entire event, was horrified and ran away. The Void Shadow opened another portal and disappeared into it, with Billie closely followed. When she exited the portal, she immediately realized the time and location of her destination - the moment Empress Jessamine Kaldwin was assassinated by Daud. But this time, through unseen manipulations, the creature somehow got Daud and the Whalers to kill both Corvo Attano and Emily Kaldwin. It then summoned yet another portal and traveled to Dunwall during Emperor Alexy Olaskir's reign. In a ceremony where Vera Dubhghoill and Lord Preston Moray's wedding was being officiated by Alexy Olaskir himself, the Void Shadow murdered both the Emperor and Vera. Billie managed to injure the creature but was almost killed before being rescued by her future self.

The future-Billie revealed that King Briam had been using an artifact to control Queen Eithne and project her into the form of the Void Shadow. The Void Shadow has its own ability to open time portals, which the King had been studying to devise a way to instantaneously transport troops across the Isles. The creature, however, could break away from the King's control, started its own scheme to change history. Despite its successful attempts, the changes it made were not crystallized, and the damages were not permanent, which allowed future-Billie to travel in time and undo the changes.

Shortly after, Billie went back to the palace to confront King Briam, but the Void Shadow appeared, kidnapping the King and stealing the Twin-bladed Knife. Billie chased the creature to where it kept the artifact, which turned out to be an altar, the very Altar on which the Outsider was created. It explained to Billie that with the Knife and the Altar finally united, it will have the power to permanently manipulate time. The Void Shadow proceeded to use the Knife to sacrifice both the King and the Queen's human body, gaining power to absorb the Altar and became a corporeal creature made of cubic blue-black stones. It claimed that it needs to feed and disappeared.

Billie, having figured out the Void Shadow would feed on voidrite, traveled to the voidrite mine with the help of Miles Severin. They arrived too late, however, as the Void Shadow had finished the task, and grown into a gargantuan flaming monster that was almost as tall as the Leviathan Causeway. The Leviathan Company's army intercepted the creature but was quickly losing ground, despite having support from heavy assault vehicles and airships. During the battle, the Void Shadow impaled one of the airships causing a voidrite explosion that severely damaged one of its arms. Billie quickly came up with the idea of filling an airship with voidrite and ram it into the monster, but requires her sacrifice in the progress. Miles Severin, however, regretting what he and his company have done, pushed Billie out of the airship and flew towards the monster. A massive explosion ensued, finally destroying the Void Shadow.

Trivia

 * The description of the Void Shadow's earliest iteration seems to bear a strong resemblance to the Shadow Walk form of Emily Kaldwin.
 * If the changes the Void Shadow made were crystalized, it would have wiped out many Mark Bearers and Void-touched individuals from history. Killing Daud would not only remove the assassin himself, but also prevent Billie from one day wielding some of the most powerful artifacts in the World. Killing Corvo and Emily would eliminate two very influential Mark Bearers of their time. Lastly, killing Vera Moray would remove Granny Rags, Morris Sullivan, and Paolo from the picture.