Though she would eventually be known as "Deathbird," Cal’syee Neramani was born into the Neramani dynasty, the family of ruling monarchs of the Shi'ar Empire. Whilst there are many races that comprise the Shi’ar Empire, at its heart is the Sh’iar race, of which Cal'syee was a member. From her birth, it became obvious that Cal’syee was different, as her physical features were regarded as an evolutionary throwback to earlier in the species’ development. Unlike the rest of her race, she possessed feathered wings and a colored display of feathers on her head. Not much is known of Cal'syee's early life, other than she was the first born child of the emperor and was soon followed by two sisters and a brother. However, it does seem that from an early age she possessed a berserker fury that would cause her no end of trouble in the coming years.
As she grew older, Cal’syee served as a commander within her father’s military. On one mission, she was tasked with retrieving a missing Kree officer in the hopes of interrogating him for information about his race’s military defenses. Her team was ambushed by some Skrulls, who were also looking for the Kree man, but she was saved by Captain Mar-Vell.
[Note: In The Untold Legend of Captain Marvel, Cal’syee is referred to as Deathbird here but she did not receive that name until she killed her mother and sister, resulting in her family name being taken from her. However, the events of this series are likely to take place prior to her exile due to the fact she still appears to be working for the Shi’ar military.]
At some point during the following years, Cal’syee’s temper got the better of her and she killed both her mother and one of her younger sisters. While the Shi’ar are often regarded as a somewhat peaceful force in the galaxy, they are also known to be a terrible and brutal empire. Under any other circumstances, Cal’syee would have been executed for her crimes. Instead, she was stripped of her name and given a more fitting one… Deathbird. She was then exiled from her home world and made a pariah amongst her own people.
Once again, few details are truly known about the next few years in Cal’syee’s life, other than she was forced to fend for herself and forge many alliances just to stay alive. In subsequent years, a number of possible children would surface, indicating Cal’syee might have given birth to at least three children during this period. The validity of their claims is uncertain but it isn’t outside the realms of possibility that she would have had progeny. [X-Men: Spotlight On… the Starjammers #2, Ms. Marvel (1st series) #10, Uncanny X-Men (1st series) #156, 345, The Untold Legend of Captain Marvel #1-3]
After a while of her wandering across the universe, Deathbird found herself on Earth. She somehow became indebted to MODOK, the former leader of AIM, and ended up working as his bodyguard in return. MODOK had recently lost control of AIM, thanks to Ms. Marvel, and he wanted to gain control of one of the facilities again. Whilst on an errand for MODOK, Deathbird spotted Ms. Marvel flying through New York and took the opportunity to dish out some revenge. She ambushed Ms. Marvel and proved a deadly opponent, thanks to her talons and energy javelins. A brutal mid-air battle took place in which Deathbird believed she had killed Ms. Marvel and she reported the news to MODOK. However, her opponent had survived and ambushed MODOK and Deathbird when they stormed the AIM base. However, MODOK managed to get into a rocket that would fire him into space and he abandoned Deathbird when she became embroiled in a fight with Ms. Marvel once more. Deathbird’s berserker fury took over and she was so intent on killing Ms. Marvel that she didn’t notices the rocket preparing for launch. She was seemingly killed when she flew into the flames coming from the thrusters. [Ms. Marvel (1st series) #9-10]
Thanks to Deathbird’s Shi’ar physiology, however, she managed to survive the blast and spent the next few months recuperating. Her partnership with MODOK apparently dissolved and she soon decided to find a way to get off the planet. She hired some mercenaries and stole some high-tech equipment in order to build a device to get her home. However, she couldn’t stand to leave without settling her score with Ms. Marvel and once again ambushed the woman as she was flying through New York. The two found themselves evenly matched but Ms. Marvel eventually came out on top. Although Deathbird escaped, the tussle with Ms. Marvel caused the hero to track Deathbird down and interrupt her theft of the electronic equipment she required. Yet another aerial fight broke out, during which some civilians were put in danger. Ms. Marvel broke off the fight to help them and was surprised to receive help from Deathbird. Cal’syee explained that the civilians were innocents and she held a code of honor that wouldn’t let them come to harm. That said, the moment the civilians were 
safe, Deathbird immediately attacked Ms. Marvel once more. In the end, Deathbird was forced to fly away after realizing her plan to steal the equipment was foiled. [Ms. Marvel (1st series) #22]
Deathbird soon tried once again to steal the components she needed to get back home and this time ran afoul of Hawkeye, who just so happened to be working as a security guard in one of the buildings she broke into. After a short fight, Deathbird realized that the raid wouldn’t be successful and tried to escape. Unfortunately for her, Hawkeye managed to catch her in a net and she was apprehended by the police. [Avengers (1st series) #189]
[Note: During her stay on Earth it is believed that Deathbird also became pregnant by an Earth man and gave birth to a human-looking girl. Though the identity of this child is not known for certain, some evidence points to her being the X-Man called Lifeguard. Whilst this isn't completely confirmed, Lifeguard eventually developed facial markings like other Shi'ar and gold skin like her supposed half-siblings White Noise and Black Light. An entry in one of Destiny's Diaries also gave a cryptic clue about Lifeguard being "mothered by war", with War being a title Deathbird would go on to hold thanks to Apocalypse.]
Somehow Deathbird succeeded in her attempt to leave Earth and headed back to Shi’ar space. For many years, she had been trying to redeem herself in the eyes of her family but she now saw that it was a futile effort. Since she had been exiled, her father had died, passing leadership of the empire over to her brother D’Ken. However, D’Ken had been seriously injured a few months before and now remained in a coma. Leadership of the Shi’ar passed onto Deathbird’s younger sister, Lilandra, who took the title of Majestrix. Still in contact with allies in the empire, Deathbird saw her opportunity to wrest control from her younger sister and began to use as many of her contacts as possible to form a terrorist rebellion. Once she felt she had enough of an army behind her, Deathbird struck, having her forces kidnap Lilandra, killing many members of the Shi’ar council in the process. She manipulated things so that all the evidence of the attack pointed towards a group of space pirates called the Starjammers. With Lilandra captive on her ship, Deathbird fled to Earth to enact the next stage in her plan. Corsair, the leader of the Starjammers, also fled to Earth and met up with some allies, the X-Men. Deathbird didn’t want him interfering, so she hired a swarm of Sidri hunters to kill Corsair.
When they failed, Deathbird saw how powerful the X-Men were and decided she needed warriors as equally strong to aid her. She struck a deal with one of the Shi’ar’s deadliest enemies, an alien race called the Brood. Deathbird and the Brood ambushed the X-Men and proved to be a powerful force against the mutants. Though the Brood were eventually killed, Deathbird succeeded in her plan of capturing Professor X, the lover of her sister Lilandra, and made her escape into deep space with her two captives. Once she was safely away on her ship, Deathbird revealed herself to her sister and offered her a deal. Lilandra would hand over control of the empire to Deathbird and, in return, Lilandra would be allowed to live out her life with Xavier. Lilandra was naturally furious with Deathbird and the two fought, but Deathbird easily bested her sister.
The rest of the Shi’ar were still oblivious to Deathbird’s involvement and, with all the signs pointing to someone from Earth being the culprit, the planet was scheduled for destruction. Deathbird wanted to make sure the planet was annihilated and so she had one of her spies within the council kill anyone who could stand in the way of its destruction.
When the X-Men caught up with her ship with the Starjammer’s help, Deathbird decided to seek assistance. Rendezvousing with a Brood ship, she sought help once more but, after the X-Men saved Lilandra and Xavier, the tide turned against her. The Brood’s ship was damaged and they lost many warriors during the X-Men’s escape. Deathbird had to think quickly for fear of the Brood’s wrath and so convinced her allies that the X-Men would be perfect breeding stock for the Brood. Her plan to have the Earth destroyed also failed when the Starjammer intervened and Lilandra released a message, telling everyone the truth. [Uncanny X-Men (1st series) #154-157]
Lilandra returned to Earth with Xavier, who had been seriously injured in his escape from the Brood. When the time eventually came for her to return to her duties, she summoned a ship to return her home. A farewell celebration was in order but, whilst the X-Men were enjoying themselves, Deathbird ambushed them with the Brood. Without any time to react, the heroes were subdued and taken away to be converted into Brood warriors. Deathbird had held up her end of the bargain and so the Brood aided her in taking control of the Shi’ar Empire. This was helped by the fact that Lilandra was too distracted with freeing her allies from Brood control to deal with Deathbird’s coup. [Uncanny X-Men (1st series) #161-162, 167]
Deathbird quickly established herself as a much harsher Majestrix than Lilandra, dedicating her reign to expansion and bolstering the already impressive Shi’ar armada. When one of her ships discovered a Spaceknight, she demanded that its advanced armor be analyzed so that her soldiers could utilize the technology. Unfortunately, the Knight’s allies showed up and rescued it, denying Deathbird the technology. [Rom Annual #4]
Lilandra wasn’t one to simply let Deathbird reign unopposed and so she teamed with the Starjammers to start a rebellion. Deathbird was well aware of the problem her sister posed, so she had her technicians write a computer virus aimed at Sikorsky, the robotic doctor on the Starjammer. The virus caused the robot to reveal the location of the ship to Deathbird’s forces, as well as the fact the pirates were after a mythic artifact called the Phalkon. When Deathbird learned of the Phalkon, she saw it as an opportunity to cement her rule and quash the rebellion. She and a squad of soldiers stormed the Starjammer and kidnapped Lilandra. After taking her back to the main Shi’ar ship, Deathbird intended to execute Lilandra but her sister managed to take advantage of a distraction and escaped. Lilandra proved to be more capable than Deathbird realized and, after ambushing her sister, was ready to kill her. Deathbird was moments away from death when her Imperial Guard arrived and the Starjammers were forced to teleport Lilandra away. With the Starjammers having abandon their vessel in the process, Deathbird gained access to the ship’s computers and discovered the location of the Phalkon. Learning that it resided on Earth, she and her forces headed off to retrieve it.
When they arrived at the planet, they discovered the Phalkon was in fact Rachel Summers, the current possessor of the Phoenix Force. Deathbird managed to overpower Rachel and kidnap her, but she and her forces were soon subdued by Rachel’s team, Excalibur. However, when the Starjammers arrived and through confusion ended up fighting Excalibur, Deathbird used the distraction to get to Rachel. She knew what power the Phoenix Force possessed and wanted to use it to strike fear into her enemies. Deathbird used a device to siphon off some of the Phoenix energy into herself, becoming Death Phoenix. Unfortunately for her, she only managed to do it for a few seconds before Lilandra cornered her and viciously attacked. Seeing their Majestrix injured, the Imperial Guard leapt to her aid and teleported her away. The loss of the Phoenix Force fragment was a bitter blow to Deathbird, as the Starjammers managed to get hold of it and empower Xavier with it. Using him as a symbol, the rebellion began to erode away at Deathbird’s rule across the empire. [Spotlight On…The Starjammers #1-2]
[Note: Spotlight on…the Starjammer #2 featured two new members of the Imperial Guard called Black Light and White Noise. When Deathbird was injured, they called her “mother,” indicating they might be her offspring. No other mention has been made of a family connection between them in any subsequent issue they appeared in]