Apocrypha whisper

"Yo, Ryuu-chan, mah man. We're in a tight spot, baby."

- "Aria" to Ryuusei. Apocrypha Whisper, also known as Voices of the Unknown, is the first Sacred Gear given to Ryuusei Amano from Lunamaria Aim with her Soul Eater technique, in the DxD: Haremonogatari continuity.

A low-tier sacred Gear, it allows the user to read the aura of everyone around its vicinity as well as slowly drift small lines of thoughts away, making it's victims forget small pieces of information.

Summary
Apocrypha Whisper was the Sacred Gear Lunamaria Aim gave to her boyfriend Ryuusei when they forged their alliance, as a token of friendship and also a gift from her girlfriend. First dismissed as just a joke, The Sacred Gear would later manifest itself during his confrontation against Sakura Nagamura. For some reason, Ryuusei instantly was able to unlock it's Balance Breaker as well, easily overcoming his current foe and finding a mid-term between his girllfriends.

Apocrypha Whisper would later be polished by Kotone in order to suit best Ryuusei instead of going out of control due to his lack of power.

Appearance
Apocrypha Whisper takes the form of a rectangular black coffin with golden details and a cross decorating the door, sealed by several silver chains around itself, which is invisible to normal humans and instead of from the user, it manifests itself in his/her proximity, stuck on the ground. Ryuusei says it oozes a rather soothing, yet eerie aura around it, similar to a small blow of hot air on the back of the neck.

Abilities
While previous users believed Apocrypha Whisper could make them read minds and alike, the true ability of this Sacred gear is enabling its user to see the aura of anyone in his line of sight, which manifests as small glows around their bodies. While not as effective as true mind-reading, Apocrypha Whisper makes possible to Ryuusei to distinguish friend from foe, as even the slightest manifestation of animosity or killer intent will be shown on his eyes. Ryuusei can also detect other people from different locations even with obstacles in the way, as he's also able to see others' auras through walls and floors.

A second ability, semi-offensive, is that Apocrypha Whisper will slowly devour away the memories of anyone in its vicinity, making them forget small portions of information as long as they stay on the area of effect of the Sacred Gear, which Kotone describes as "a small piece of her mind floating away until it completely dissapears".

Weaknesses
Being a sight-oriented Sacred Gear, Apocrypha Whisper has the logical weakness that the auras seen are limited to Ryuusei's own line of sight, and as such, assaults coming from behind are most likely its blind spot. It's aura reading can also be blocked by special spells meant to disguise one's presence, although once one starts moving, the user will be able to see it's aura.

The area of effect is limited to 10m cubic from the coffin, and once summoned, Ryuusei can't move it from its initial place, although he can store away and summon it on a different location so that he can scan and aura-read on a it, while also putting himself at risk of surprise attacks. Apocrypha Whisper also has no true offensive abilities, being more of a support-type Sacred Gear.

Balance Breaker: Mysterious Aria
Mysterious Aria, also known as Melancholic Song of the Cruel Singer, is Apocrypha Whisper's Balance Breaker, which strangely was immediately unlocked by Ryuusei in its first summoning. Breaking the seals and opening its doors, the coffin reveals from inside a doll-like independent avatar which always stands by Ryuusei's side.

The doll, nicknamed "Aria", is completely conscious, and can read the auras and minds of everyone in an area of 50m cubic, although Ryuusei is unable to see from it, instead, Aria can communicate with her host and give him advices about how to deal with his foes with the information she gather herself, strangely speaking in Kyoto dialect from Ryuusei Perspective. A second ability, more offensive-based, allows Aria to unleash a magical soundwave which not only stun anyone in its vicinity, it'll also completely vanish any thoughts from its victims for a small amount of time, more or less like a small reset on their brains.

Quotes

 * "Ryuu-chan, mah man, this is a tigh spot~!"
 * "Let me help you, baby. You know you can't live without me, sweetheart~."
 * "Dat bitch is ruining the party. Ryuu-chan, time to fill her with smacks~!"
 * "Baby, hold my hand and say I'm your Sacred Gear."

Trivia

 * The images used are from the innocence Grave of Maria from the D. Gray-man Series.
 * Appparently, despite not being invisible like the initial form, only Ryuusei can hear Aria's advices, as everyone will only hear small whispers from her.
 * It is unknown why the Sacred gear speaks in Kyoto dialect, although being stored inside Lunamaria, who herself speaks in Kyoto dialect, might have something to do with it.
 * The idea of its Balance Breaker is slightly based on the concept of Stands from JoJo's Bizarre Adventure series.
 * An "aria" is both a name and a form of music which originally any expressive melody, usually, but not always, performed by a singer, a reference to its balance breaker.