Nightmare Masque

"Truly, the odds of you being just teleported to our world were already astronomically slim, and to be given a Sacred Gear such as this, well… The chances of this ever happening again are so close to zero it might as well be zero."

- Phobetor, regarding Roland having [Nightmare Masque].

Nightmare Masque ( ナイトメア・マースク, N aitomea Masuku), or Dark Mask of the Incubus  is a high-tier Sacred Gear which contains a copy of the Greek God of Nightmares:  Phobetor. It is one of the Sacred Gears that make the Oneiroi Triumvirate, along with [REDACTED] and [DATA NOT FOUND]. It is currently possessed by Roland, the second Rook of Rias Gremory.

It was first activated after Roland's encounter with Freed when he first arrived in the world of High School DxD.

Summary
Not much is known of Nightmare Masque's origins. Not even the sealed spirit knows exactly when it was first placed in the system. The earliest memory that Phobetor can remember is being seduced by a Fallen Angel, within the body of his first user.

The Sacred Gear has been seen throughout history since at least the Middle Ages, where the supposed first user was initially being seduced by a Fallen Angel. This failed, and subsequent user's of the Sacred Gear, despite many factions best efforts, have always either died early deaths, or have gone mad, and activated Breakdown the Beast. The last user to do this was Kazuki Kurosawa.

Appearance
In it's Unawakened Form, Nightmare Masque takes the form of a masquerade mask, which can be any color of the user's choosing.

After Nightmare Masque has been awakened, it's appearance changes drastically. The mask covers the user's entire face, witht he exception of two peepholes for eyes. Again, the color can be anything the user chooses when they summon it.

When the user morphs their head, the Sacred Gear will seem to 'sink' into their face, allowing for such a change to occur.

Abilities
Nightmare Masque has several abilities that have been seen so far. Including:


 * 'Nightmare Manipulation '(ナイトメア・マニピュレーション, Naitomea Manipyureshien) - The standard ability of the Sacred Gear, which allows the user to transform or 'shapeshift' their arms, legs, wings if they have them, and head into any number or combination of mythical or normal creatures.
 * In it's Unawakened Form, the user can only morph their hands, feet, and face.
 * Aura of Madness (オーラー・オブ・マドネス, Ora obu Madonesu) - A passive ability of Nightmare Masque, the user has an aura about them that makes people who either do not know the user personally or have enough magical ability to stave off it's effects hate them at first sight, or outright fear them.
 * This is the ability that causes many users to go mad. Years of neglect and harsh treatment result in traumatized individuals. Phobetor has called this ability an 'unfortunate oversight by my progenitor'.
 * Voice of Phobetor (ボイス・オブ・フォビートー, Boisu obu Fubito) - An ability created by the Strongest User of Nightmare Masque, Lukas Gallagher, the user taunts or insults a target, focusing Aura of Madness on a single person, manipulating the individuals emotions. In the right conditions, it can cause a target to experience violent hallucinations and temporary madness.

Drawbacks
"N-No… I don’t want t-to be a m-monster… People d-don’t like m-monsters. I-I want people t-to… like m-me…"

- Kazuki Kurosawa, when Roland met him in the depths of [Nightmare Masque].

Nightmare Masque does have its fair share of drawbacks.

One of the many is the disadvatage placed on the user if they have not awakened the Sacred Gear fully, called 'Unawakened Form', this form only allows the user to change their face, hands, and feet. Also, and this is one of the worst effects of the Gear, is the constant night terrors the user suffers until the Gear is 'awakened'. The night terrors grow in intensity over time, and is another contributing factor to the mental health of most users.

Aura of Madness is another drawback. Users will find a hard time socializing or making friends when everyone around them hates them because of the Aura.

Nightmare Manipulation doesn't affect the chest of the user, which can be exploited.

Trivia

 * Nightmare Masque's main ability is based on Phobetor's ability to appear in the dreams of mortals as beasts and monsters.
 * Phobetor's admiration for Fallen Angel wings is a reference to the real lore of the Oneiroi, which are said to have black wings.
 * It took me 4 months to eventually finalize this thing.