Serin Osman

Admiral Serin Osman, formerly SPARTAN-019, also known as Oz, (Service number 39489-72738-SO ) is the Commander-in-Chief of the Office of Naval Intelligence, inheriting the role from Admiral Margaret Parangosky after the end of the Human-Covenant War.

Early life
Born in 2511, Serin was abducted in 2517 as a SPARTAN-II candidate. She was given the designation Serin-019, and trained under Chief Mendez along with the rest of the Spartan-II candidates.

SPARTAN-II Program and ONI career
"BB sometimes wondered what kind of operational Spartan she would have made, just the averagely terrifying kind or a full-blown angel of death."

- Black-Box

Osman did not successfully complete the augmentation process, only receiving the genetic and biochemical enhancements before her body started to reject the rest. While she failed the augmentation process, she still possesses a few of the enhancements, although nothing skeletal. At 14 years old, the Office of Naval Intelligence took custody of her, educated her, and put her into the ONI commanders' program. They also repaired the damage done by the failed augmentation process, but the other Spartans thought her dead.

Considered as a protégé to Admiral Margaret Parangosky, the Director of Naval Intelligence, the Admiral groomed the former Spartan for a potential future as her successor. Osman considered herself the only person who the Admiral would always forgive even if she failed. In order to hide her status as a former Spartan, she adopted the surname "Osman". Though people often assumed she was of Turkish descent based on her name and appearance, she did not actually know whether this was the case; though the information on her pre-Spartan identity was readily available to her, she never looked at the files.

Kilo-Five
By 2553 Osman held the rank of Captain. She was hand picked by Parangosky to lead up a black operations team known as Kilo-Five, which was composed of smart AI Black Box; a civilian professor and Sangheili expert Evan Phillips; ODSTs Staff Sergeant "Mal" Geffen, Sergeant Lian Devereaux, Corporal "Vaz" Beloi; and SPARTAN-II Naomi-010 to ensure Sangheili insurgency. Using Phillips, Osman got a meeting in January with Avu Med 'Telcam, a member of the Servants of Abiding Truth on New Llanelli. She agreed to give him weapons to aid in his upcoming insurrection, but it was part of a ploy to destabilize the Sangheili. Later she met with Parangosky to confirm Kilo-Five's members, as well as being given the AI Black-Box and a secondary mission to find Dr.Catherine Halsey who had disappeared with Blue Team after the Battle of Onyx. Upon arriving aboard the UNSC Port Stanley Osman transitioned the ship into Slipspace, and told Naomi-010 who she was. Naomi-010 revealed to Osman that they thought she had died. Osman then proceeded to tell the others about her past in the SPARTAN-II program, revealing that it started when she was six. This shocked the other members on the ship and angered Naomi-010, creating the very tension Osman had hoped to alleviate. Reaching New Llanelli, Osman was surprised to see 'Telcam had kept his word, and gave him tagged Sangheili weapons.

However, she was approached by Tom Muir, a colonist who had managed to survive on New Llanelli even with the colony's glassing. Brought aboard the ship, Osman was angrily questioned by Muir about why she was meeting with the Sangheili. Osman made up a story that they were exchanging fallen bodies that Muir bought into, saving Osman from needing to kill him. After a quick mission extracting Mike Spenser from Reynes, Osman went to aid the that was damaged outside Venezia. However, the ship was destroyed by Venezia.

She went on several missions aiding the Servants of the Abiding Truth and continuing the insurrection against Arbiter Thel 'Vadam, and even taking Dr. Catherine Halsey into custody for "committing acts likely to aid the enemy" and meeting with Fred-104, Kelly-087 and Linda-058 and the Spartan-III's Tom-B292, Lucy-B091, Ash-G099, Mark, Olivia and Chief Mendez in ONI Research Facility Trevelyan.

Sangheili civil war
After 'Telcam began an armed insurgency against 'Vadam, Parangosky ordered Osman to intervene during the Servants of the Abiding Truth's attack on Thel 'Vadam's keep. While the Lord Hood and the UNSC Infinity openly aided 'Vadam and defeated the attackers, Osman secretly destroyed several of 'Vadam's ships, allowing the Abiding Truth's forces to escape. Her team also rescued Evan Phillips, who had been stranded on Sanghelios previously. She also rescued 'Telcam (much to his anger) from 'Vadam's forces. After this operation, Osman and her team were assigned to track down Naomi's father Staffan Sentzke, who was seen in the company of the Kig-Yar Skirmisher Sav Fel.

Requiem campaign
By 2558, Osman has risen to the rank of Admiral and had taken Parangosky's place as head of the Office of Naval Intelligence. During the later stages of the Second Battle of Requiem, she was contacted by Captain Thomas Lasky, informing her about Doctor Halsey's abduction by the Promethean Knights. She had been recommended to either relocate Halsey or keep her imprisoned, but instead chose neither: telling Lasky to carry out Parangosky's orders to kill Doctor Halsey.

Trivia
At Admiral, Serin is the highest ranking SPARTAN-II.

List of appearances

 * Halo: Glasslands
 * Halo: The Thursday War
 * ''Halo 4
 * Spartan Ops