After the demise of Ra's al Ghul in Arkham City, Nyssa assumed leadership of one of the warring factions within the League of Assassins. Motivated by a desire to make amends for her father's actions, Nyssa's rebel faction fought tirelessly to prevent the loyalists of Ra's from gaining control of the rebel's Lazarus Pit. They understood the grave consequences that would follow if the loyalists obtained access to the powerful restorative abilities of the Lazarus Pit. Prior to the Arkham City incident, a tape recorded by Ra's Al Ghul was discovered in Elliott Memorial Hospital. In the recording, Ra's entrusted the leadership of the League to Nyssa's sister, Talia, in the event of his death and Batman's refusal to join their cause. Ra's expressed his lack of trust in Nyssa's ability to lead the League, deeming her too compassionate.

Lara Croft is an English archaeologist, treasure hunter and tomb raider. Born to an aristocratic family, Lara is generally disinterested in upper class society, finding it stifling and boring. She takes far more interest in delving into the secrets of the past and finding what is believed to not even exist. Lara's expeditions have led her to search for some of the most powerful and dangerous artifacts in the world as well as uncovering some of the most mysterious places in Earth's history. Lara's exploits are legendary, even garnering a reputation, though occasionally that reputation is less than flattering. Lara is often in race against time with those who seek the same relics she does for nefarious intentions. Lara has thwarted many groups and individuals who are incredibly well equipped or powerful, including crazed religious cults, mad scientists and even gods. Lara will often lock up some of the more powerful relics in her manor, in order to keep them out of anyone's hands but her own and if the situation requires it, she may even destroy the artifact if need be.

Batman, who was poisoned by Joker with the latter's blood, went to find Freeze in order to get the cure. He discovered that the Penguin had kidnapped Freeze, and tracked him to the Museum. Batman soon found Freeze locked in a display case under a heat lamp, and was barely staying alive with the use of a plug that injected liquid nitrogen into his body, which kept it at sub-zero temperature. Batman got Freeze his suit and his freeze gun back and brought him the Penguin. Freeze got revenge by stepping on the Penguin's broken hand, only eased up when Batman told him to stop and locked the Penguin in one of his own display cases. Batman asked for the cure, but Freeze explained that it was too unstable for use. Batman realized that he needed to get the restorative element the cure required: a sample of blood from Ra's al Ghul. Freeze returned to the old GCPD Building at Amusement Mile while Batman went after Ra's. After Batman recovered the blood sample, Freeze was able to complete the cure and quickly locked it away in his safe. Batman demanded the cure, but Freeze refused and destroyed one of the two vials of the cure. He informed Batman that Joker had Nora and Freeze ordered Batman to bring Nora back to him, and launched a full-scale attack against Batman. Batman was able to defeat Freeze and smashed the protective dome around his head to punch him, but stopped after a Joker hallucination from his worsening health. When Batman attempted to retrieve the cure, however, he discovered that Harley Quinn was able to break into the safe and stole the other vial. Batman pursued her, at the insistence of Freeze, and agreed to also look for Nora. In exchange, Freeze gave Batman the Freeze Blasts that he had developed to help him break into the Steel Mill.

Vicki Vale had dreamed of becoming an award-winning journalist. Sometime after succeeding at this, Vicki Vale wrote a news article about the question of the real identity of the Red Hood. When Batman came into prominence, she did not expect to have to cover him. Vicki Vale was seen interviewing Bruce Wayne about his plans for Christmas Eve. Sometime after, she, along with her team in Blackgate Prison when Black Mask and his men invaded it. She was imprisoned by some of his mobsters in a cell until Batman arrived and beat them down, only for her to back away in fear, begging Batman not to hurt her or her team, not knowing that he was not a threat. Sometime after Arkham City's ribbon-cutting ceremony, Vicki Vale continued to cover the Mayor's unimpressive record in curbing crime and corruption despite heavily populating Arkham City with the most dangerous criminals and instituting unpopular curfews across Gotham. Vicki was assigned to cover a press conference hosted by Bruce Wayne about Arkham City.

Koriand’r was the second of three children. Her sister, Komand’r was first in line to succession, but owing to an illness that stripped her of her natural ability to convert ultraviolet light into flight energy, she was deemed unfit to rule, and so the title of Queen would fall to Koriand’r. When both sisters were sent to train with the legendary Warriors of Okaara. During the proceedure, Tamaranean forces loyal to Komand’r came to her rescue. While everyone was distracted, Koriand’r broke free, using her newfound powers, which she would also use to rescue her sister, who would immediately overpower Koriand’r and arrange for her execution. Koriand’r escaped and eventually found her way to Earth, where she gained the assistance of the Teen Titans. Koriand’r chose to remain with the team, taking on the name “Starfire".

As a child, Kara Zor-El witnessed the devastation of Krypton before she was sent to Earth on a mission to protect her infant cousin, Kal-El. Arriving on Earth decades too late, she discovered that grown-up Kal has been imprisoned due to his hideous actions as the High Councilor of the Regime over the last five years. Still determined to protect her family and its legacy, Kara will fight her cousin’s enemies as Supergirl. Sometime after that, Black Adam had found her ship and brought it to Kahndaq. Later, Kara and Black Adam rescued an imprisoned Wonder Woman from Themyscira. After being incapacitated by Cheetah, Kara was saved by Diana, who almost killed Minerva. When Harley Quinn intervened, Diana stabbed her through the torso, causing Kara to realize the Amazonian's true colors. After cauterizing Quinn's wounds with her heat vision, she battled and defeated Diana and went to speak to Superman in the Fortress of Solitude. Upon confronting him on Diana's actions, Kara learnt the truth about her cousin's fall from grace and his murder of the Joker, along with many other criminals and former allies. Should the player choose Batman, the ending results in a battle following the defeat of Brainiac and ultimately leads to the defeat of Superman and his allies. As a result, Superman is placed in the Phantom Zone after the alliance against Braniac disbanded. Batman begins to trust Kara as a result, and offers her a position in the Justice League.

Viper's only known role in the Battle of Typhon would be protecting and escorting the Ark to the IMC airfield housing the transport vessel IMS Draconis. He would later be seen, along with Slone, in the hangar of the ship prior to its emergency takeoff. Afterwards, Viper would fly into the skies in his Titan, featuring numerous upgrades that significantly improved his flight time and missile tracking. He would engage in a fierce battle with squadrons of Militia Crows, showcasing his superior skills in aerial combat. Ultimately, he would unleash a barrage of missiles at the Widow, which unfortunately resulted in Jack Cooper and BT-7274 plummeting from the sky and landing on Barker's dropship. Despite facing fierce opposition from the Militia's aerial troops, Viper pressed on to IMS Malta to prevent Jack and BT from reaching the Draconis. The two pilots engaged in an intense fight on the outer hull of the battleship, where Jack emerged victorious, inflicting severe damage to Viper's Titan. (Alternate) Viper survived his crash from his titan and was able to be recovered by Blisk after he activated a flare and they both made it off ghr planet Typhoon and Viper was able to rebuild his titan.

Born in the Frontier, Dr. Ashleigh Reid learned early that the only person who was going to look out for her was herself. Though much of her origins are unknown, she did have a brother who died when he was very young. Some time before the year 2643, she was hired as a mercenary to steal a potential new energy resource in the Outlands, and did so by becoming Horizon's assistant. After three years had passed while searching for a way to avert the impending energy crisis that threatened the Outlands, she then departed with Horizon on a dangerous mission to prove the existence of Branthium. After Horizon successfully extracted the Branthium from a black hole, Reid betrayed her and left her to die in the black hole. By the time of the Battle of Typhon, Ash was a successful mercenary Pilot in the Apex Predators, piloting a customized Ronin-class Titan. Following the initial assault by the 9th Militia Fleet, Ash would deploy with the Predators into battle. Eventually, the group would come across the Vanguard-class Titan BT-7274, Piloted by Tai Lastimosa. Ash would use her Titan's Phase Dash to sneak up on BT, ripping several Batteries out and causing the Vanguard to be severely damaged. Believing the threat taken care of, Ash would then retreat to the Dynamic Testing Facility. Following her supposed death at the hands of Jack Cooper, Ash would be rebuilt by arms manufacturer Vinson Dynamics and contracted to lead their own military force.

Before being hired as Blisk's second-in-command, Slone acted as a sniper during the Nexus Plantation Massacre in which she allegedly wiped out the entire town by herself. Slone would deploy alongside Blisk, Richter and Ash during the opening stages of the Battle of Typhon, intending to wipe out any survivors of the failed Militia assault on the planet. She would be the first of the Apex Predators to cross the landing site of Jack Cooper and Tai Lastimosa, attempting to destroy the Vanguard defending them, BT-7274. However, she would ultimately fail in killing the Titan alone, but instead distract it long enough to allow it to be finished off by her comrades. The morning following the attack, Slone would direct a number of IMC search teams around the crash site of MCS James MacAllan, eventually instructing Salvage Team Gamma to retrieve the Vanguard-class Titan for salvage. Slone would later be given charge of several captured riflemen, but was ultimately ordered to simply execute them, which she would show no remorse for.

Born on Earth in the Core Systems, Blisk began his career as a fighter at a young age in the Thunderdome games in the Outlands, a fringe region in the Frontier. When the Titan Wars began, Blisk enlisted in the IMC’s army and quickly climbed the ranks to commander. However, the politics and corruption of war pushed the Blisk into the life of a mercenary, where he could control his own fight and answer to no one but himself. As a mercenary, he provides Combat Intel and Counterinsurgency services; his first contract with the IMC concluded with his outfit making enough money to retire to a tropical paradise. Five years after the Battle of Demeter, Blisk entered his newly-staffed mercenary group - the Apex Predators - into a contract with General Marder and the ARES Division, a research wing of the IMC. Blisk and the Predators deployed to the planet Typhon, where they were to oversee security operations and take charge of the IMC garrisons on the otherwise remote and uninhabited planet. Their ultimate objective was to protect the Fold Weapon, a newly discovered ancient superweapon on the planet, as well as its power source, the Ark. After Slone's death, Blisk stood atop BT's cockpit on foot to confront the Militia Pilot one last time. Instead of finishing him off, he congratulated Cooper on his victory. Whether out of respect for the Pilot or sticking to the letter of his contract, he explained that since his contract was completed, he had no reason to kill Cooper, since he does not kill for free. Instead, he left Cooper an Apex Predator calling card, saying that he earned it, offering him a standing invitation to the Apex Predators in case Cooper ever decided to "fight for himself" rather than the Militia. General Marder hotly protested and ordered Blisk to kill Cooper; Blisk refused, as he claimed it was not in their contract and that he had "other people with money to see".

Sarah served as an intelligence and logistics officer and field commander for the Militia, working in tandem with Bish to process intelligence and direct ground forces during battles with the IMC. There was one notable instance where she took to the field herself: in the mission The Three Towers, while Militia forces engaged the IMC defenders to keep them busy, Sarah led a squad of covert operatives to silently assault and sabotage the Repulsor Towers protecting the IMC base from the dangerous local fauna. When on the ground and Sarah dons her jump kit she is a skilled pilot, While slow in the gauntlet Sarah is still a skilled Pilot, Fighter and Commander using her custom-made Smart Pistol MK5 and her P2011 Pistol. As Commander of the Marauder Corps Sarah also has her own titan, A Vanguard-Class Titan named MOB-1316.

Monarch’s design was based on the salvaged, badly burnt up remains of two Vanguard-class Titans recovered by the IMC from the Battle of Typhon. While the Vanguard-class was designed by the Militia for armed recon deep behind enemy lines, the IMC’s mandate for Monarch focused on flexibility through survival and support options, to serve many operational roles. Although Vinson Dynamics was unable to reverse-engineer and replicate key aspects of the original Vanguard design, they brought their own R&D innovations when creating Monarch. One of these innovations is her Upgrade Core, which allows her to improve her combat abilities during a battle, based on options set by her Pilot. Monarch also has an impressive ability to draw power from enemy Titans to recharge her own shields, or the shields of her friendly Titans. Despite the IMC and Vinson Dynamics’ efforts to maintain secrecy, several shipments of early Monarch production variants invariably leaked onto the black market, allowing mercenary Pilots and independent manufacturers across the Frontier to discover her true potential.

BT-7274 was the first Vanguard-class Titan created by the Frontier Militia, around two years following the Battle of Demeter. He served with Tai Lastimosa for 973 days three years before the Captain's eventual death on Typhon. As a Vanguard-class Titan, BT is designed for operations in hostile territory and behind enemy lines. As such, he is equipped with many pieces of equipment reminiscent of older Titan designs such as the Atlas, with an emphasis on survivability over expendability. This includes the inclusion of two dashes and a recharging Bodyshield system. The Titan is also designed for versatility and capable of equipping and adapting a number of new loadouts on the fly, being able to equip a VTOL Hover, Laser Core or Particle Wall seemingly without issue.

Bear was one of the pilots of the 6-4 involved in the Battle of Typhon. He, along with Gates, Davis and Droz, assisted Jack Cooper and BT-7274 in boarding the IMS Malta to assist the Militia fleet pursuing IMS Draconis, so they could capture The Ark. The team would help Cooper take out the bridge of the vessel, before capturing it and later using it to assist in the militia assault on the Fold Weapon.

Davis was the captain of a Frontier Militia squadron that attacked IMC Airbase Sierra, located on the fourth moon of Demeter. He piloted a Titan and fought alongside Captain Droz until he was either incapacitated or successfully defeated the IMC reinforcements. Sometime following the Battle of Airbase Sierra, Davis, along with Captain Droz, left the Militia and joined the 6-4, a Militia-sympathetic independent faction of bounty hunters and freelance Pilots. They were recruited by Gates, a former captain of the IMC who they battled against during the attack on Airbase Sierra.

Droz was the captain of a Frontier Militia squadron that attacked IMC Airbase Sierra, located on the fourth moon of Demeter. He piloted a Titan and fought alongside Captain Davis until he was either incapacitated or successfully defeated the IMC reinforcements. Sometime following the Battle of Airbase Sierra, Droz, along with Captain Davis, left the Militia and joined the 6-4, a Militia-sympathetic independent faction of bounty hunters and freelance Pilots. They were recruited by Gates, a former captain of the IMC who they battled against during the attack on Airbase Sierra.

Gates was the captain of an IMC Marine squadron that was deployed to IMC Airbase Sierra, located on the fourth moon of Demeter, in response to an attack by the Frontier Militia. She piloted a Titan and fought alongside Captain Alavi until she was either incapacitated or successfully defeated the Militia attackers. Sometime following the Battle of Airbase Sierra, Gates defected from the IMC and formed a Militia-sympathetic independent faction of bounty hunters and freelance Pilots, known as the 6-4. She recruited Captains Droz and Davis, two Pilots from the Frontier Militia who she battled against during her time at Airbase Sierra.

Talia al Ghūl was the second-in-command of the League of Assassins, the daughter of Ra's al Ghul. A master of hand-to-hand combat and swordplay, Talia had dueled with Batman on several occasions and considered him an honorable opponent. Talia first met Batman when he saved her from an attack in Shiva's palace, but in the process he was stabbed with a poison dagger. Talia took Batman, nursed him back to health, and had to unmask him to tend to his wound. She introduced him to her father, who wanted to form an alliance with him. But Batman discovered Ra's al Ghül's murderous goals. A highly trained and very intelligent young woman, Talia al Ghül, the eldest daughter of Ra's al Ghül and the second-in-command of the League of Assassins, was considered by many to be the deadliest female assassin in the world.

Selina Kyle is allegedly Carmine Falcone's younger daughter. It is believed that at a young age, Carmine and his wife Louisa gave Selina up for adoption for unknown reasons, forcing her to fend for herself in the streets of Gotham. She turned to thievery to survive, learning martial arts and gymnastics to develop her own style. Eventually, she created an identity for herself as Catwoman after hearing rumors about Batman. Arkham Asylum's former administrator, Quincy Sharp, won the election to become Mayor of Gotham, he incarcerated all prisoners and mental patients from Blackgate Prison and Arkham Asylum within a sealed-off perimeter known as 'Arkham City', including Catwoman, who was convicted on March 11th, and charged with robbery. Lawlessness reigned and armed mercenaries patrolled the walls of the prison city to ensure no one attempted to escape, with Sharp hoping that the society of villains housed inside would kill each other and rid Gotham of its worst criminals. While in Arkham City, Catwoman decided to break into Hugo Strange's Office to retrieve her loot that was confiscated upon her arrest. TYGER Guards capture her and take her to Strange, where he conducts a psychological interview with her to discover her criminal motives and her relationship with Batman. Catwoman refused to answer his question until he threatened her by revealing he has a TYGER agent who has Holly Robinson in sight, waiting for an order from Strange to kill her if necessary. She then infiltrated Two-Face's old campaign office in order to find the Confiscated Goods Vault plans, beat up members of Two-Face's gang, but ended up captured by Two-Face. After she is saved by Batman, she doesn't elaborate on any knowledge on what is going on in Arkham City or on what Hugo Strange is up to. Batman told her that she's not safe in Arkham but Catwoman told him she'll be fine. She promptly left, having no further interest in the conversation.