Ballas was an Orokin Executor prior to the fall of the Orokin Empire. Suggested to be the lover of Margulis, whom he attempted to convince to destroy the Tenno for her own safety, an act which ultimately proved futile. He is also believed to be the Orokin primarily responsible for the development of Transference and the creation of the Warframes.
Lore
General
Much like Corrupted Vor, who proclaims that he is "energy", an immortal being incapable of death, Ballas and other high-ranking Orokin appear to be undying, as elaborated in the Fragments. It is currently unknown whether the process of Continuity – the transference of an Orokin mind into a new body – is the key to this immortality or not.
Fragments
Fragments recovered throughout the system also reveal Ballas' involvement in the creation of Cephalon Ordis, who he created from the mind of a mercenary warrior named Ordan Karris, bound to servitude with modified memories as punishment for the latter's attempt at killing him.
Synthesis
The Detron Crewman's Synthesis imprint also suggests that Ballas was involved with the creation of what would become the Sentients, a rather ironic action given that the Tenno would be created and deployed to fight the Sentients when they later turned on the Orokin.
The Second Dream
Dialogue during The Second Dream states that Ballas held the rank of Executor, and was implied to be romantically involved with the Archimedian Margulis. She had been protecting the survivors Zariman Ten Zero, whom she is later ordered to kill. Margulis refuses to kill them and is ultimately executed, with Ballas participating in the trial. After this Ballas would continue Margulis' work on Transference to develop the Warframes.
Apostasy Prologue
Ballas officially makes his first appearance in Apostasy Prologue, interrupting the Operator when they meet the Lotus in person. The Orokin apologizes in advance, which left the Lotus to question what he is sorry for, remarking that she is not his lover, Margulis. Ballas replies that she is merely imprisoned within before waving his hand, releasing an energy wave that disconnects the Lotus from her own pod.
This causes the Operator to wince in pain, distorting the player's screen in a similar fashion to The Second Dream. The Lotus then seems briefly surprised and then appears to recognize Ballas, calling out his name. He vows never to abandon her again while offering his hand. The Lotus, no longer protesting Ballas' claim that she is Margulis, takes off her mask before taking his hand. The two then walk together into a blinding light in front of the Tenno before disappearing.
The Sacrifice
Ballas makes his second appearance in The Sacrifice where he is shown cooperating with Sentients battling a rogue Warframe, 
Excalibur Umbra, whom Ballas subdues and destroys. While the Operator searches for the Lotus they come across the scene on Earth and end up rebuilding Excalibur Umbra after detecting traces that originate from Lua and locates Ballas's Vitruvian.
The Operator discovers that Excalibur Umbra is sentient and learns through his memories that he was originally an Orokin Dax soldier transformed into a Warframe after being injected by a unique strain of the Infestation under the guise of treatment, as punishment for interfering with Ballas's betrayal due to the death of Margulis, while being controlled by Ballas through a unique Transference Bolt and went mad after being forced to kill his son, Isaah. The Vitruvian also reveals that Warframes are created through the Helminth's Infested strain intended to be used as mindless drones against the Sentients in the Old War, but this failed with the Warframes quickly going feral and becoming uncontrollable, resorting to the use of the Operator's Transference. The Vitruvian also reveals that Ballas was the one who exposed the weakness of the Tenno and their Warframes to Hunhow as part of a deal betraying the entire Orokin Empire and defecting to the Sentient.
After the Operator calms Excalibur Umbra, they confront Ballas. Ballas finds that he can no longer control Excalibur Umbra due to the Operator, and suffers a seemingly fatal stab to his abdomen. Lotus, in the form of Natah, suddenly arrives and retrieved Ballas, much to the Operator's disbelief and confusion.
Chimera Prologue
After chasing The Man in The Wall through Lua and dropping down into the shaft inside the Reservoir into the same chamber during the Apostasy Prologue, the Operator enters a portal and spots Ballas. The Orokin is revealed to be Sentient-turned and is mourning for the loss of his narcissistically beautiful Orokin body all while cursing the Lotus for her deception, by stealing his perfect death. As he rambles, his eye suddenly glows, which he implies to be the Lotus's vision. He eventually offers his sword 
Paracesis, which he calls the "Sentient slayer", to the Tenno in preparation for war with the Sentients. As they grab the sword, Ballas abruptly turns to face them as the Lotus's whisper for the Tenno can be heard.
Erra
Ballas was leashed by Erra while the Sentient was discussing the war with his sister. He confirmed that the Orokin are truly gone, Corpus and Grineer are at war against each other, and the Tenno are her enemy.
Unnamed Cinematic
*This can be accessed by clicking the third card inside The New War quest in the Codex console.
Erra is telling Natah that their mother is gone and urges her to finish the war as she still has her fire. Natah notes that she remembers ordering the Tenno to attack Erra and he was apparently destroyed. Erra objects and states that she remembers wrong and will need time to completely heal from what the Makers had done to her. Natah points at leashed Ballas and asks if he is one of the Makers.
Erra then suddenly grabs and throws Natah at the pedestal behind him. She is trapped in some kind of trance and her body slightly expands. Erra tells her once more to finish the war and drops the leash from his hand. Now the freed amalgam Ballas stands tall for the first time since his incarceration. Both Erra and Ballas then silently stare at Natah.
Trivia
- Ballas is voiced by Max Howarth.
- So far, Ballas has been the narrator of the newest line of Prime introduction videos/trailers.
- In
Saryn Prime's introduction video, his dialogue indicates that he developed Saryn as a means to fight the Infestation, as well as that her design may have been inspired by Margulis' love for the natural environments of Old Earth. - In the Vauban Prime trailer, it is indicated Vauban was created to fight the Corpus. The narration also implies that the ancestors of the current Corpus faction were active during Orokin times and that they may have had a hostile relationship with the Orokin, at least sometimes.
- In Nekros Prime's intro video, Ballas seems to directly address his fellow high-ranking Orokin, stating, "Your graces, we who are beyond death, have forgotten the simple power of fear."
- In the video for Banshee Prime, it is indicated that Prime Warframes, if not Warframes in general, were made to create a set of units who are much more unique and capable than the mass-produced and decrepit Grineer.
- In Valkyr Prime's intro video, Ballas mourns the loss of animalistic aspects the Orokin tossed away for their immortality and beauty. He warns that the Warframes, which retain a primal nature, should be feared. Even though they are Tenno-controlled, they are merely biding their time to eventually strike at their Tenno and Orokin masters.
- Thus far, this is the only trailer to not mention the name of the Warframe being showcased.
- In Oberon Prime's preview video, Ballas talks about the errors of greed, as the greedy do not think of the consequences, evident with the Grineer who often plunder the forests of Earth. Thus, Ballas talks of Oberon as the avenger of the forest, the one who will place judgment on the Grineer who have contaminated the greenery for too long. And through the blood of these defilers will the forest grow stronger.
- In Mirage Prime's video, Ballas recognizes the suffering that the Tenno--or perhaps the individuals who were used to create the original Warframes--endured to become what they are. He states that Mirage "played the fool" while others "writhed and raged in the vice," echoing some of the scenes of Alad V's torturous vivisection and experimentation on captured Warframes (and hinting at how Warframes were created from infested, tortured humans). Mirage's tricks ultimately allowed her to "distort [Ballas'] design."
- The introduction ends with Ballas stating no one is laughing anymore except Mirage. At the very least, this line suggests Mirage proved to be an effective killer, the only one left laughing on the battlefield. The phrasing may also allude to greater significance relating to the Tenno/Warframe betrayal Ballas warns of in Valkyr's introduction.
- In
- Ballas' Sentient-hybrid transformation, in Chimera Prologue, foreshadows a new kind of enemies, Sentient/Corpus Amalgam, which was reveal during Devstream 124.
- In Chimera Prologue, Ballas still has his left leg attached to his knee, but it is gone in Erra. This is probably an indication that his amalgamation progresses further.
- So far, it seems that Ballas and Nihil are the only two Orokin who have been defeated by the Tenno for their actions with Ballas being wounded by Excalibur Umbra and then remade an Amalgam and Nihil being imprisoned in an oubliette by the Tenno with the help of the glassed victims.
