Light Nostrade is the head of the Nostrade mafia family.

Source:Wikipedia

Dalzollene (ダルツォルネ) is the leader of Neon Nostrade's bodyguards and Kurapika's direct superior.

Source:Wikipedia

Fujimoto is a priest at the Southern Cross Monastery, a Paladin in the True Cross Order (the title awarded to the strongest exorcist), Shura Kirigakure's mentor, and foster father to Rin and Yukio Okumura.

Abilities:
He was qualified as an Knight, Dragoon, Doctor, Aria and Tamer. He has a cait sith familiar, which he called Kuro.
Shiro is a man dedicated to his duties and was considered the strongest exorcist. Stealing the demon-slaying sword Kurikara, Shiro and Mephisto ultimately used the sword to seal the demon heart of the son of Satan and Yuri Egin. Shiro then adopted Yuri's children, Yukio who did not inherit Satan's power, and Rin, full inheritor of Satan's powers.

Source:Wikipedia

D.O.B: 27th December
Blood-Type: O
Height: 180cm
Weight: 70kg

Plot:
Yukio is Rin's younger twin brother.
When it was discovered that the woman impregnated by Satan was going to have twins, it was believed that Satan's powers would be split between them. Due to the weakness of Yukio's body, however, he did not inherit any of Satan's powers, thus being born fully human with the full extent of Satan's powers going to Rin.
Yukio did, however, receive a spirit wound at birth from his brother, which allowed him to be aware of demons for as long as he can remember. Yukio secretly trained to become an Exorcist from the age of seven in order to protect Rin through the help of Fujimoto. Even though he and Rin argue a lot, Yukio truly cares about his brother. Fearing Rin will be consumed by his demonic nature, Yukio often berates him for his impulsive actions and reckless attitude.

Abilities:
It is often stated that Yukio is considered a prodigy, having already acquired the title of "Meister" in both the Dragoon and Doctor class, while ordinarily most people would aim for Meister in only one class (both are still fully qualified exorcists). He is currently ranked a Middle First class exorcist.
In combat, he dual wields pistols.

Source:Wikipedia

D.O.B: 12月27日
Blood-Type: A
Height: 173cm
Weight: 63kg

Plot:
Rin Okumura is the fifteen-year-old protagonist of the story and the son of Satan, born from a human woman and an inheritor of Satan's powers.
His powers were sealed at birth into a demon-slaying blade, Kurikara (倶利伽羅), by Mephisto Pheles, the True Cross Academy principal, allowing him to live a normal human life for nearly 15 years with his twin brother Yukio and his foster father Shiro Fujimoto.
Rin becomes aware of his true identity after Kurikara can no longer seal his powers, setting off a chain of events that lead to the death of Shiro at the hands of Satan, who attempts to drag Rin back to the demon realm, Gehenna.
Mephisto Pheles later confronts Rin, who demands Mephisto to let him join the exorcists against the demons. Mephisto personally enrolls Rin into the True Cross Academy so that Rin can pursue his goal to become a Paladin and to defeat Satan.
While currently an Exwire, Rin wishes to obtain the biggest rank of an Exorcist, Paladin, to prove that Fujimoto did not want to use him as a weapon.

Abilities:
Rin can access the power he has inherited from Satan through drawing Kurikara. The sheath acts as a portal to Gehenna, which, when the blade is drawn, returns Rin to his demon form.
In his human form, Rin does exhibit a number of physical traits that are signs of his demonic nature, which are intensified in his demon form.
In both forms, Rin can control incredibly destructive bright blue flames, a trademark sign of anything related to Satan. However, when he draws Kurikara, the magnitude of the flames dramatically increases and often leads to Rin being "consumed" by his own flames and losing his mind.

Rin also has a Cat Sith familiar, Kuro, which was initially Shiro's.

Source:Wikipedia