Aliases/ Nicknames: Is always willing to accept them, especially if its from a cute girl but normally goes by his last name (Bui)
Age: 144 but appears to be very early 20's
Height: 6'2
Weight: 175
Race: Arrancar
Affiliation: Hueco Mundo
Numero: 4 Cuatro Espada
Aspect of death: Intoxication
Reiatsu color: Violet
Physical Description:

Hollow hole: right where his heart would be.
Mask fragment: What appears to be headphones covering his ears
Espada tattoo: On his chest opposite of his hollow hole.
Personality: Bui is sarcastically very polite and has excellent manners, similar to that of Gin Ichimaru. However unlike Gin he shows his true colors fairly often. Bui is incredibly impulsive as he believes he has nothing left to lose in the underworld, he often requests to leave and does recon work on the off chance of something exciting happening. He greatly enjoys fighting and views it from a huntsman(or serial killer, your call) mentality which causes him to view his opponents as prey that he enjoys to play with.
Fear: Being a hunter there is nothing more that he fears than becoming the prey. Having someone look down upon him and toy with Bui's mind because killing him would be too quick.
History:
Bui became a hollow by utter coincidence. Once a raging teenager he was attacked by a renegade hollow viewing him as a tasty meal. A shinigami showed up to expel the hollow however he ended up being killed by the hollows deceptive power. But the reckless creature's attacks caused a building to collapse upon its skull crushing it and also severing Bui's soul chain. Thinking quickly he grabbed the shinigami's blade and killed the hollow, eventually turned into one himself. He found hollow life boring, wandering from place to place growing in strength as he traveled but nothing really seemed to captivate his interest. Decades passed as he advanced in menos ranks to vastro lorde before being approached by Cillian Folamh. Aside from the normal promises of power or luxury Cillian truly seemed to understand what Bui really wanted, fun. The cero espada promised Bui that the most exciting and fun events he would ever find were just waiting for him at Hueco Mundo so long as he pledged his allegiance.
Zanpakto:
Sealed:
Bui's zanpakuto is a very large form of a naginata. Despite the size he can swing it around like its nothing more than a simple wakizashi which often deceives his opponents. On the hilt end of the blade is a slight ring which Bui has a dark purple rope tied to. On occasion he has been known to swing it by the rope or treating it like a kusarigama.

Resseruction:
Command: Scream, Ruido! (Noise)
Bui's large zanpakuto emits a high pitched shriek as begins to bend the light around Bui distorting his image as it vanishes into white smoke. When sight of him becomes clear his mask fragment has formed armor around his body with three antennae that resemble chords for amplifiers.

Resseruction powers:
Sónico Barrera: (Sonic Barrier) Bui constantly emits an intense vibration from his body making it difficult to come into contact with him.
Canción de Cuna: (Lullaby) Anyone who can hear the frequencies emitting from Bui are subject to illusions of his creation. Often times he uses them to distract and taunt his prey before finishing them off. When combined with his Gemelos Sonido he can make it appear as if he can multiply.
Canción de la Inmersión(Song of Immersion) When the tip of one of the chord like antennae makes contact with an enemy their minds begin to truly beleive the illusion is real, which means Bui;s illusions can actually hurt people. The antennae are 6ft long with three stemming from the back of his neck.
Specialization:
(Primary)Mid-range combat
(Secondary) Pesquisa
Skills: He is a remarkable tactician and enjoys playing head games with his opponents.
Abilities:
Latido (heart beat) Bui is able to pulse out a small frequency that he infuses with his reiatsu. He can use this like sonar with his Pesquisa, increase his bala speed, turn it into a cero, or increase his sonido speed.
Pesquisa Due to his sound wave manipulation Bui's Pesquisa is much more accurate like a sonar. Due to this he is utilized as a sensor and is often the first sent for recon.
Hierro His hierro is sturdy enough to be able to block lieutenant level shikai with his bare hands.
Garganta
Cero
Cero Oscuras
Gran rey Cero
Cero Pulsante (Pulsing cero) a radial version of the cero attack weaker than when directed at someone still more powerful than bala.
Bala Bui's bala is one of the fastest in the espada
Gemelos Sonido so fast he creates afterimages of himself