Xerxes Averian

"Despair is the building blocks of foundation. The Shinigami faced despair, in the form of countless wars and bloodshed. The Arrancar, and Hollow by extention, went through despair just trying to stay alive. Do you not see? This is what we thrive on, despite the Shinigami's humorous goals of peace. Once they wake up, can they understand power that derives from despair."

- Almayo Vinas to Madara Kawahiru

Xerxes Averian (クセルクセス, Averian Kuserukesu) is an Arrancar in Akujin's Arrancar Army, and holds the title of Quinto (5th). Unlike the other top five, Xerxes leads his own group under the direct order of Takashi Sora.

Personality
Xerxes is extremely cruel, ruthless and devoted to Sora's cause. He refers to his enemies as "mister (plus a nickname)" in mocking respect and often makes big smiles and casual talks before attacking. He has also proven himself to be very clever and resourceful. Despite this, he remains soft-spoken, rarely having much to say unless speaking to an opponent, or giving out orders. He is rather arrogant and fairly confident in his abilities, as shown when he encounters Koga Tensei and states that he will fight at exactly the same power level as a Lieutenant, saying it will "be more than enough for a simple Seijin."

During his fight with Renge Yamato, it is revealed that Xerxes considers the essence of war to be despair. He also hates to fight unless prompted or given orders by Sora. However, in combat he shows ruthlessness. Xerxes has shown himself remorseless with this, beheading an opponent that was pleading for mercy. He believes solely in the thought that Arrancar are pure beings because they do not have absolute ideals (ie. in the case of Shinigami, calling Hollow evil).

Powers & Abilities
Immense Spiritual Power: Xerxes has an incredibly high reiatsu, and is able to fight on par with Tōkaru Mokushima, a Seijin Master well known for high spiritual power. It is because of this high spiritual power that Xerxes has strong Hierro. He is also just below the power level of the top four Arrancar Five, but compares himself to be stronger than a good handful of the other four.
 * Power Inhibitor: Curiously, he appears to be able to limit his powers, which when removed, can increase his power exponentially. He calls these levels, and claims that his full power is acheived at level 10. When at level 1, his power level is equal to that of a Captain-level Shinigami, and when at level 3 he was able to effortlessly fight back Ken'ichi Misora. At level 5, he was shown able to easily overwhelm Renge Yamato (while he refrained from unleashing his Zanpakutō's Bankai).

Master Swordsmanship Specialist: Xerxes is highly proficient in swordsmanship. He is also exceptional at using acrobatic tricks in conjunction with his sword and possessing a highly technical swordsmanship skill while engaged in combat, seemingly being unfazed even in combat with another master swordsman. He was capable of not only holding his own against Koga Tensei in swordsmanship, but also overwhelming the young Seijin with sheer ferocity and strength. Mixing his mastery of his sword's unique shape with the special ability it has, he is coldly proficient during its use and application. His skill in swordsmanship has been shown to be powerful enough to take down his opponent with a single precise strike.

Sonído Master: Being an Arrancar of the top five in Sora's army, Xerxes is a master of the Sonído art. He has shown to be highly proficient at using it. At level 4, his skill with Sonído allows him to catch Seijin Master Ken'ichi off guard during most of their fight. Unique to him alone, Xerxes had the ability to mask his sonído's sound, to prevent being heard.

Cero Oscuras: Despite being in a sealed state most of the time, Xerxes can utilize the Espada's black cero. It is a black Cero with a dark blue outline to it, which Xerxes states to be similar to Renge's cerulean Getsuga Tenshō. Xerxes's Cero Oscuras is powerful enough to blast Koga's mask away and destroy a large part of a Rukongai village.

Zanpakutō
The name of Xerxes' Zanpakutō has not been revealed. It's appearance is that of a European Rapier, with a golden rectangular guard. The blade itself is very thin, but extremely powerful nonetheless. It was strong enough to take on the full brunt of Tōkaru's Getsuga Tenshō, and be able to block a massive cero from a Hollowfied Koga; in both cases, the blade did not break.


 * Resurrección: Not Yet Revealed

Trivia

 * Xerxes comes from the eastern lands of the Fullmetal Alchemest universe.