Kingslayer

It warned us about coming of The King and that once he arrives, it will hunt him down.
But for now, it lets us keep itself in a safe place where we can study it.

Kingslayer is a sentient and sapient Wrong that takes the form of a sword. It possesses mind and body affecting powers.

Properties

Sapience and sentience

Kingslayer is capable of both understanding and using speech, reading, writing, and speaking in any language it hears or sees (the third and fourth one only when it's held by someone). It remembers its every hunt against The King. Even without any receptors, it is capable of perceiving the environment around it with all five senses.

The blade

While its blade looks completely blunt, Kingslayer itself showed that it's capable of easily cutting any known material. Additionally, whenever it swings, some of the sharpness is sent through the air, making it capable of cutting targets up to 5 meters away from it.

Choosing the bearer - the call

Whenever Kingslayer finds itself without a bearer, it will start to generate a mind-affecting field around itself which doubles its radius every minute no living being capable of using it touches it. Any such creature will feel a strong compulsion, growing in intensity, to touch the sword. The compulsion quickly gets so strong, the affected beings will stop perceiving any dangers between themselves and the sword, possibly hurling themselves out of high places, walking into the bodies of water, or walking into the traffic, with no regard for their own well-being.

Adjusting the bearer

Once a being capable of holding the sword touches it, it dies. Instead, the sword gains complete control over its body, pouring its consciousness inside it. While possessing the body, it is capable of doing anything it was capable of, though its strength and speed grow considerably.
Over the next few days, Kingslayer modifies the body of its bearer. Pieces of metal start to grow out of it, creating monstrous armor, each different in its shape, depending on the bearer. Muscles of the bearer start to grow, following the natural growth that would happen during the exercise. They also gain some height. As the body changes, its endurance and toughness increase. Regenerative abilities start to show up.
A fully changed bearer can withstand a couple of shots that would be fatal for normal people should any of them pierce their armor. Still, they are vulnerable to decapitation, and killing them releases the sword, immediately beginning the search for a new bearer. It is not recommended to kill the sword-bearer as it will cause more unnecessary deaths.

Sensing The King

Kingslayer can sense the exact location of The King once he appears in the dimension it's in.

Rebellion

The area 10 meters around the Kingslayer protects all living beings from any influence of The King or his growing realm.

Dimension jump

Once Kingslayer manages to kill The King in the dimension they both are in, it will disappear from that reality to show up in the one The King will next manifest.

Related myths:
The tale of the Kingslayer
Current status:
Dormant. According to its own words, Kingslayer will wait until The King appears. It doesn't react to any aggressive actions against it, even finds them amusing.

Purpose

According to its own words, Kingslayer exists only for one purpose, to kill The King. It is adamant in its task and once its target shows up, it is impossible to draw its attention from it.

"And what would happen if both of you showed up in a world totally devoid of any life? Wouldn't killing him there possibly send him to the world where his presence would endanger living beings?"
"The King has to die, no matter what"

— Interview with Kingslayer

Appearance

When looking at it, it's hard to describe Kingslayer as a sword. Its blade looks as if someone slapped together some blunt metal plates and connected them with pieces of scrap and wires. In this chaos, there is nothing one could really call an edge. The "blade" is 90 cm long. Going lower, the crossguard is asymmetric with one of its sides sticking 50 centimeters out. The grip of the sword is made out of irregular and often pointy rings, making it look like the sword is really painful to hold. Whole Kingslayer is the color of dark bronze with some oxidized black parts.

Containment problem

Until The King arrives, Kingslayer doesn't care where it stays and when asked, can move its host to any place. According to what it says, once The King shows up, it will break out of any containment.

Destruction

No method of destroying the sword has been found and as it can deal with another Wrong that will show up in the future, The King, no further ways of destroying it are researched openly.