Tainted Vessel: The Nightmare Warrior

History
The Nightmare Warrior was a failed vessel created by the Pale King to create the Hollow Night. The Nightmare Warrior was unable to succeed in ascending from the Abyss and instead had to find another way out of the abyss. Similar to the other escaped vessels The Nightmare warrior did manage to leave the abyss, and on its war it grew stronger, and began to bare a similar form to that of the Pure Vessel in its prime, but on the way the Nightmare Warrior, somehow was tainted by the Nightmare Heart, corrupting its power and bending its will. It then made its way to the Howling Cliffs where it lies dormant feeding off of the nightmare essence it gathers from travellers.

Tainted Vessel
The Tainted Vessel can be found in a cave in the Howling Cliffs. It will stand before a small altar and stare at the Knight until spoken too or dreamnailed. The Tainted vessel fight will then begin.

The Tainted Vessel is moves fast but attacks slowly. It has four main attacks in its first phase.

PHASE 1
Nightmare Nail: The Tainted Vessel swings twice with its nail, each successful hit deals 1 mask of damage. A glow of nightmare essence follows the nail.

Nightmare Beam: The Tainted Vessel points its nail at the Location of the knight and charges a beam of nightmare essence.

Nail Charge: The Tainted Vessel charges forward in a straight line left or right. This can be done from the air.

Nightmare Burst: The tainted vessel charges nightmare essence for a moment before a burst of the energy explodes around it, damaging two masks.

PHASE 2
In its second phase the Tainted Vessel attacks faster and gains two new attacks.

Nightmare Spike: The Tainted Vessel slams its nail into the ground and a spike of nightmare energy emerges from beneath the point where the Knight was when the attack started.

Nightmare Strikes: The tainted vessel slashes three times around the Knight, one at each side and one time from above the Knight.

After The Battle
After the Knight has defeated the Tainted vessel it will explode into a cloud of nightmare essence and void. It will leave behind its cracked mask, its weapon, the nightmare nail and its cloak. If these are dream nailed it will transport the Knight into the dream world where the Knight can fight a more powerful version of the Tainted Vessel: The Void Nightmare.

The Void Nightmare
The Void Nightmare is the original and more powerful form of the Tainted Vessel. It will attack the Knight upon sight and has two phases similar to the original boss.

In its first phase the Void Nightmare will use more powerful version of his original attacks and an additional attack, VoidStrike

Voidstrike: The Void Nightmare puts its hands out to the sides and a spiral of void and nightmare essences will errupt from both sides, spanning the width of the stage but not the height.

In phase 2 the Void Nightmare uses stronger versions of its previous attacks and gains two extra attacks: Nightmare Orb and Void Ord

Both the spells create an orb of energy that will approach the Knight. They last until the orb hits a wall or until five seconds have passed. The Void orb absorbs a small amount of Soul from the Knight.

Once the Knight has defeated the Void Nightmare it will get an opportunity to "communicate" with the Tainted Vessel's ghost from before it encountered the Nightare Heart's influence. The ghost will not say anything but instead simply nod in the direction of the Knight before disappearing.

Rewards
If the Knight defeats the Void Nightmare and interacts with the ghost it will result in a charm being found on the floor where the Tainted Vessel's mask used to be. This charm is called the "Nightmare Call" and it transforms the Knights vengeful spirit/shade soul into a blast of nightmare essence that will deal lingering damage to foes it hits and freeze them temporarily.