Fraccion are various numeros arrancars who serve directly under a specific Espada they are only allowed to have a total of eight or less under their regime there are a few Espada's who prefer to work alone such as Ulquiorra, Aaroniero, and Zommari. Side note while Stark and Lyintte have a Fraccion Relationship it is in fact the two are one. The Fraccion are frighteningly loyal to their Espada Masters such as Barragan's or Harribel's even more to Aizen.

FRACCION:

2#BARAGGAN LUISENBARN:
Choe Neng Poww: Zanpaktou: Calderon Remains of hollow mask: Horns on chin (Deceased Killed by Captain Komamura)

Charlotte Cuuhlhourne: Zanpaktou Reina De Rosas Remnant of Hollow Mask: Tiara with Horns (Defeated by Yumichika Current Fate Unknown)

Avirama Redder: Zanpaktou: Aguila Remnant of Hollow mask: Beak like Helmet (Deceased Decapitated by Izuru)

Findor Carias: Zanpaktou: Pinza Aguda Remains of Hollow Mask: Helmet (Deceased Split in Two by Hisagi)

Gigo Vega: Zanpaktou: Tigre Estoque Remains of Hollow Mask: Sabertooth tiger like Helmet (Deceased Killed by Soifon)

Nirgge Parduoc: Zanpaktou: Mamut Remnant of Hollow mask: Helmet with Short Tusks

3#TIA HARRIBEL:

Apache: Zanpaktou: Cierva Remains of Hollow Mask: Horn (Deceased burned to death by Captain Yamamoto)

Mila Rose: Zanpaktou: Leona Remnant of Hollow Mask: Three Sectioned tiara/crown, necklace (Deceased burned to death by Captain Yamamoto)

Sun-Sun: Zanpaktou: Anaconda Remains of Hollow Mask: 3 hair clip extensions (Deceased burned to death by Captain Yamamoto)

5# NOITORA JIRUGA

Tesla: Zanpaktou: Verruga Remnant of Hollow Mask: Jaw like circlet around his forehead (Unknown defeated by Captain Zaraki)

6# GRIMMJOW JAGGERJACK

Shawlong Qufang: Zanpaktou: Tijereta Remains of Hollow Mask: weird looking helmet (Deceased shattered into ice by Captain Toshiro)

Edrad Leones: Zanpaktou: Volcanica Remains of Hollow Mask: Eye holes which rest on his nose resembling glasses (Deceased Killed by Ikkaku)

Nakeem Greendina: Zanpaktou: Unknown Remnant of Hollow Mask: Mask over half his face (Deceased killed by Rangiku Matsumoto)

Yylfordt Granz: Zanpaktou: Del Toro Remains of Hollow Mask: Small Helmet (Deceased Killed by Renji)

Di Roy Linker: Zanpaktou: Unknown Remnant of Hollow Mask: Bulky helmet similar to a hammerhead shark (Deceased Killed by Rukia)

8# SZAYEL APORRO GRANZ:

Lumina: Zanpaktou: Unknown Remains of Hollow Mask: Unknown (Deceased Eaten by Szayel Aporro Granz)

Verona: Zanpaktou: Unknown Remains of Hollow Mask: Unknown (Unknown vanished after Szayel left)

Medazeppi: Zanpaktou: None Remains of hollow Mask: Mask covering right side of his face (Deceased Killed by Uryu)

10/0#: RAJIK FISHER

Yammy Rigalo: Zanpaktou: Ira Remnant of Hollow Mask: Jawbone with 8 teeth (Currently Fighting Byakuya & Zaraki alongside with Rajik)

Hisako Qufang: Zanpaktou: Zetsymaru Remnant of Hollow Mask: Skull Necklace around her neck (Currently Fighting Byakuya & Zaraki alongside Rajik)

Goro Overschvank: Zanpaktou: Kumo Remnant of Hollow Mask: White headpiece resembling to some degree Byakuya's headpiece (Currently Fighting Byakuya & Zaraki alongside Rajik)

Fracción Relationships

BARRAGAN'S FRACCION

Baraggan's Fracción are fiercely loyal to him - possibly more so than they are to Aizen - and willingly obey his every command. His Fracción treat him like a king (referring to him as "his majesty"), with Poww going even further and seeing Baraggan as a "god". Much like Baraggan himself, they are all very arrogant and boastful. Baraggan was angered when four of his underlings were killed, but out of anger for their failure rather than concern, and goes so far as to call them "trash". Contrasting the teamwork shown by Harribel's Fracción, Baraggan's Fracción are highly independent of one another, and are never shown speaking directly to each other during the fake Karakura Town battle. This disregard for their allies in battle is shown most notably by Ggio Vega, who knocks Soifon into his fellow Fracción, Nirgge Parduoc, apparently killing the latter and showing absolutely no concern for him (though in the anime, when Ōmaeda apparently defeated Nirgge, Ggio sounded surprised that the latter was beaten, though it was more out of shock and fear for his own safety than for that of his comrade's).

HARRIBEL'S FRACCION
Harribel's Fracción respect her and take everything she says seriously. They themselves appear to have a strained, yet somewhat comical, relationship with one another. Despite this, they work quite well together, and are capable of using powerful combination attacks. Unlike most of the other Espada, Harribel actually genuinely cares about her subordinates and angrily assaulted Captain Tōshirō Hitsugaya when they were defeated by Head-Captain Genryūsai Shigekuni Yamamoto. She even commends them and acknowledges the fact they tried their best instead of scorning them for their loss.

NOITORA'S FRACCION
Noitora lone Fracción, Tesla, idolizes him and remains loyal to the end, despite Noitora occasional mistreatment of him. Noitora himself cared for Tesla's well being enough to warn him of Kenpachi Zaraki's power and told him to run (though he insulted him while doing so). Tesla did not seem to have his admiration for Noitora while Noitora was the eighth Espada at that time; it is unclear what changed his mind. Tesla is shown shedding tears when Noitora is killed.

GRIMMJOW'S FRACCION

Grimmjow's Fracción are loyal and obedient, and were all members of a group of roaming Adjuchas led by Grimmjow before they became Arrancar. They disregard their comrade, Di Roy, considering him the weakest of Grimmjow's five Fracción, and reluctantly accepting his 'assistance' during Grimmjow's assault on Karakura Town. Edrad Liones scornfully calls him 'an Arrancar in name only'. All of them are quite cocky, much like Grimmjow, and most appear rude and unwilling to even bother learning their opponents' names (with the exception of Shawlong). After they were killed during their invasion of Karakura Town, Grimmjow showed no signs of anger or sorrow, just surprise at the fact that an entire squad of Arrancar (excluding himself) was eliminated by "a bunch of low-level Shimigami". Interestingly, none of Grimmjow's Fracción used honorifics while referring to him.
Szayel's Fracción are more like drones than henchmen and he shows little to no concern over them, even going so far as to cannibalize them in order to replenish his strength and regenerate his wounds, as seen during his fight with Renji Abarai and Uryū Ishida. Szayel apparently treats them as mindless lab-rats whose only real purpose is to defend him from his enemies and for his experiments. Amongst the Espada, Szayel has by far the most Fracción.

RAJIK'S FRACCION

Rajik's Fraccion are Extremly Loyal but very childish and hotheaded, while Hisako just like her Espada Master is a naturally evolved Arrancar meaning she naturally removed her mask unlike most arrancars who artificially became arrancar's with Aizen's help such as Yammy but Goro is a Clone of Rajik's former lover Neliel altered in age and power he is the only levelheaded subordinate in Rajik's Fraccion he acts as Rajik's personal bodyguard while Yammy and Hisako being the hot headed short tempered one's attack the enemy head on. Rajik treats his Fraccion like his family he is very caring about them but he can be very dark to them as well seen in numerous occasions during battle and whenever Hisako and Goro fight over petty matters.