Cal'syee was born with atavistic features and was fiercily proud of it. Unfortunately, the atavism also caused her to experience fits of uncontrollable rage that eventually forced Cal'syee to kill her mother and younger sister. For these crimes she was stripped of her name and became known as Deathbird. She lost the right to the throne and was exiled from the Shi'ar Empire.
Wanting the throne, she rebelled against D'Ken, who was emperor at the time, and allied herself with the Brood to usurp him and, later, Lilandra (who succeeded D'Ken). She eventually usurped the throne and became empress of Shi'ar, although she had to face many rebellions. A group of Skrulls maimed her wings and forced her to abdicate in their favor.
Deathbird sought the help of Lilandra's allies the X-Men but, once the Skrulls were removed from the throne, Deathbird chose not to sit on it, and she abdicated again in favor of Lilandra. Due to her surprisingly good job while reigning, once the Kree-Shi'ar War was over, Lilandra named Deathbird viceroy of the recently annexed Kree Empire.
Horseman of War
Deathbird was later recruited to serve Apocalypse as the Horseman War. She retrieved the Living Monolith along with X-Man Bishop for Apocalypse to use in the Twelve. Deathbird and Famine were teleported away by Mikhail Rasputin after Apocalypse's defeat.
While in space, she began a relationship with the time-displaced Bishop. The two ended up confronting each other over a plan to defeat the Ruul, and Deathbird was presumed dead after being ejected from a spaceship.
Rise and Fall of the Shi'ar Empire
Deathbird was rescued by the Imperial Guard, but Lilandra imprisoned her because she posed a threat to her rule .
On his quest for vengeance against the entire Shi'ar race, Vulcan was captured and incarcerated in the same maximum security installation that housed Deathbird. Released by a member of a secret order that wished D'Ken to lead the Shi'ar once more, Vulcan himself released Deathbird.
Vulcan was enthralled by Deathbird, and they became romantically involved. He promised to put his quest for vengeance on hold. Deathbird convinced Vulcan to finish the healing process that the Shi'ar members of the secret order had begun on D'Ken, who remained in a coma since the M'Kraan Crystal incident. When D'Ken discerned Vulcan's feelings for Deathbird, he invoked an ancient Shi'ar custom and invited Vulcan to marry Deathbird and become part of Shi'ar royalty.
Vulcan and Deathbird were married in front of the M'Kraan Crystal just as the X-Men, Lilandra, The Starjammers, and the Shi'ar loyal to Lilandra attacked. During the chaos that ensued Vulcan killed D'Ken (as he didn't promise not to kill him) and assumed the throne of Emperor of the Shi'ar Empire, with Deathbird as his Empress. During the fight Polaris crushed the ribs of Deathbird's husband and she instructed the Imperial Guard, still loyal to the ruling family, to protect them as they fled.
Vulcan's rule was initially compared to Lilandra's as the Shi'ar thought Cal'syee's husband another weak human. Vulcan however proved that he was a strong emperor and the people fell in love with him. During the Starjammers escape from their prison planet Cal'syee was severely injured by Polaris.
At some point after Vulcan's death she was captured by the Providian Order. However they wasn't interested in Deathbird, but only in her child - hybrid of atavistic Shi'ar and powerful Mutant. Sharada Darthri experimented on the baby and infused it with Kree geneline.
Spider-Man and the X-Men
Deathbird was later seen to still be pregnant and possessed by a group of rogue symbiotes who attacked S.W.O.R.D. and teleported to the X-Men headquarters. She was separated from the symbiote and later taken into custody.
Dawn of X
Due to the threat of the Titans impending war against the Shi'ar Empire, Majestor Kallark had Deathbird brought in by the New Mutants to serve as an adviser to Xandra and prepare her to rule the Empire. However, this decision was controversial and Oracle sent the Shi'ar Death Commandos to attack the ship carrying her. 
The New Mutants were swiftly defeated and captured, but Deathbird fought her way through the Death Commandos to rescue them. Deathbird then returned to Chandilar and tried to murder Oracle for her betrayal. A battle ensued between the two factions, with Deathbird facing off against Gladiator. However, Princess Xandra ended the conflict and, as punishment, forced Oracle to stand by her side alongside Deathbird. Around this time, Deathbird also began a flirtatious relationship with Sunspot.
Later, on Chandilar, a band of Stygian rebels captured Xandra. Deathbird recruited the X-Men to help find the missing Majestrix. The X-Men eventually discovered Urr's plot to kill Xandra as he believed it would end the tyranny of the Shi'ar Empire. The X-Men defeated Urr and returned Xandra to Deathbird's side.
During Dormammu's attack, Deathbird and the Imperial Guard defended the Aerie and its moon from an army of Mindless Ones. M'Baku and Shuri assisted the Shi'ar in repelling the enemy forces, though Deathbird vowed to kill them if they attempted to betray her. The combined forces ultimately succeeded in destroying Dormammu's Mindless Ones. Despite her hatred for the Wakandans, Deathbird offered to open official lines of communications between the Shi'ar and Wakanda.
Deathbird later accompanied Majestrix Xandra and the Imperial Guard to the Keep, a space stationed operated by S.W.O.R.D. When the Lethal Legion attacked, Deathbird grabbed Xandra and flew her to safety until Storm arrived.
Some time later, the Shi'ar Empire held the Great Ornithery Festival. Sunspot caught Deathbird's attention after claiming to be a leader of the X-Men. She asked for his assistance in protecting Xandra, as Oracle and Delphos had seen visions of a possible threat to her life. Sunspot assembled a team of X-Men to meet with Deathbird at a distant location. Sunspot was also contacted by the Imperial Guard, who believed Deathbird had returned to her villainous ways and kidnapped Xandra. The X-Men made their way to a shuttle around the Great Kythri Wormhole where Deathbird had taken Xandra. When questioned about the Imperial Guard, Sunspot attempted to lie to Deathbird which leads to her choking him. Xandra stopped Deathbird from attacking as she trusted Sunspot, but they were suddenly attacked by the Sidri that Deathbird had hired to test the X-Men. The Sidri impaled Deathbird in the back with a teleport mine, leading to her captivity.
- Claws: Deathbird has claw-like nails that can be used in fight, except when flying.
- Natural Winged Flight: able to reach 63 mph. Maximum 6 hours of flight, without extra weight. Maximum load, 330 pounds. Notably, she must have her arms free, but she might use her hands while flying. Her wings are sharp spurs that can be used to fight while on flight.
Exceptional hand-to-hand combatant, trained in Shi'ar methods of armed and unarmed combat; skilled at hurling javelins; expert in Shi'ar law; cunning military strategist.
Shi'ar Javelins, which extend to 3-feet in length and can be thrown with deadly force. Deathbird has also used a javelin that releases a noxious gas on impact. Some javelins can project blasts of electricity when the tips of two javelins touch each other.
Shi'ar starships.
- Deathbird had also killed her mother. It was learned after Lilandra screamed "Matricide!" while leaping towards her in Uncanny X-Men #156.
- 83 appearance(s) of Cal'syee Neramani (Earth-616)
- 5 minor appearance(s) of Cal'syee Neramani (Earth-616)
- 17 mention(s) of Cal'syee Neramani (Earth-616)
- 79 image(s) of Cal'syee Neramani (Earth-616)
- 6 quotation(s) by or about Cal'syee Neramani (Earth-616)
- 3 victim(s) killed by Cal'syee Neramani (Earth-616)