- "Sara Lance. I am Mallus! Soon, I will be free and your world will know unendurable pain!"
- —Mallus to Sara Lance[src]
According to Rip Hunter, Mallus was perceived as a myth, existing throughout all of time, and known by many different names in all types of languages. Rip also states that the Time Masters, were too frightened to even speak his name. 
Agent Ava Sharpe mentioned Mallus became a threat after the Legends "broke" time. After Kuasa was resurrected by Nora Darhk, a servant of Mallus, she told her that Mallus requested her services. Mallus was hunted throughout time by Rip Hunter for years. Mallus later ordered Nora to travel to London 1895 and resurrect Damien Darhk. During the ceremony, Rip Hunter interrupted them and demanded to Nora to speak with Mallus. Without hesitation, Nora agreed and within seconds, Mallus took possession of her body and stated to Rip that it was a pleasure to meet him. Rip then demanded to see his true form, Mallus wickedly laughed and said that he wouldn't live when he saw his true form and claimed that while Rip was mortal, he was a god. Just before Damien was resurrected, Mallus stopped possessing Eleanor.
Mallus was not seen or heard from again for a while until the Legends once more crossed paths with the Darhks in the year 1000 A.D. while endeavoring to rescue a younger Martin Stein from Vikings and preventing the US from becoming New Valhalla. During a pitched battle between the two sides, Damien came rushing to his daughter's aid, using his glowing orb to transport them away. As they did so, White Canary grabbed on to Darhk and was transported suddenly to a dark, desolate place, the very dimension in which Mallus was imprisoned. Mallus called out to her from the darkness, never revealing his face or true form. Declaring his name when asked who he was, Mallus swore that he would soon be free and that the entire world would soon be subjected to unendurable pain. Canary could only look on in stunned terror as a huge, black hand reached out towards her from out of nowhere as ghoulish laughter echoed all around, before she was yanked back into her own world by Agent Sharpe through a portal hovering nearby.
While possessing a young Nora Darhk in 2017, Mallus soon attracted the attention of the notorious warlock John Constantine who subsequently broke into the mental hospital Nora had been placed in to exorcise her. Constantine unfortunately had no idea what he was really blundering into and recklessly tried to banish Mallus from the girl with an ordinary exorcism without knowing the entity's name first; Mallus merely laughed it off and derided Constantine's efforts, citing his failure to save Astra, his own eternal damnation and his efforts to save the soul of Sara Lance. Frightened by Mallus' power, Constantine fled the hospital and went in search of Sara.
Mallus didn't have to wait long before Constantine returned to the hospital with the Legends in tow to help him. Once he, Sara Lance and Leo Snart had revived the catatonic Nora inside a magical seal known as the Triangle of Solomon, Mallus soon emerged and greeted them, focusing on Sara and remarking on how he had been expecting her; that she would soon see his true form when he took her back to his world for all eternity. Wasting no time, Constantine launched into another exorcism, this using Mallus' name to amplify it. Laughing ghoulishly, Mallus once more shrugged off Constantine's exorcism without even trying and simply strode out of the Triangle, bellowing that Constantine's powers were useless against him. Telekinetically tossing the group aside, Mallus quickly scrawled a temporal displacement symbol on the ground and cast the group back in time to the 1960s version of the same hospital before withdrawing back into Nora.
Determined to gain possession of Sara Lance, Mallus reached out telepathically to her in the 1960s and began haunting her, giving her hallucinations and dredging up her worst memories so as to incited enough fear and rage within her to prime her for possession. He was foiled in this regard by Constantine who coached Sara through the process of resisting possession. Meanwhile back in 2017, Mallus revealed himself to Zari and Ray in Jitters after they attempted to help Nora reenter normal life and mocked their efforts. Roaring, screaming and bellowing as the building shook with tremors all around, Mallus ignored their appeals to Nora and threw Ray against a wall when he got too close. In response, Zari moved to grab Nora by the arm which unexpectedly started to badly burn the entity. Horrified and roaring with pain, Mallus accused Zari of being 'one of the six' and tried to fire a swarm of glass shards at her. Unfortunately at that exact moment Nora reasserted control over herself with the help of Sara, temporarily silencing Mallus.
Though he currently hasn't appeared in physical form yet, whilst possessing Nora, Mallus is shown to be a sinister individual whose existence even scared the Time Masters. Mallus also possesses an air of supreme arrogance, referring to Rip Hunter as "hopelessly mortal", compared to his presumed status as a god. When Sara Lance accidentally entered the very dimension he was imprisoned in, he vowed to her that once he is freed from his prison, he will make her entire world know unendurable pain.
Powers and abilities
Demonic powers: Mallus is a mysterious and extremely powerful demonic being who possesses tremendous amounts of supernatural power. So far he has shown the following powers:
- Demonic possession: Mallus displays the ability to possess and speak through Nora Darhk. This possession is characterized by his target's eyes turning bloodshot.
- Exorcism immunity: Mallus was unable to be affected by John Constantine's exorcism rituals and magic.
- Power bestowal: Mallus was able to grant Damien and Nora Darhk powers similar to those obtained through the Khushu Idol and a few extra powers.
- Photokinesis: Mallus was able to grant Nora the powers to control condensed light blasts while being channeled through her.
- Thermokinesis: Mallus was able to grant Nora the powers to control fire and ice while being channeled through her.
- Mediumship: Mallus was able to grant Nora the ability to communicate with deceased spirits as well as himself. It's possible he granted Damien the same ability.
- Superhuman durability: Mallus can grant Nora the ability to take massive hits with no harm brought to her. He hit Nora's head on a table multiple times at high speeds without even damaging her physically, stating that she feels no physical pain.
- Superhuman strength: Mallus made Nora significantly strong, enough to use her nails to easily scratch on a tele without any signs of slowing down, strain or fatigue.
- Biological manipulation: Mallus made dark colored goo appear from Nora's mouth.
- Restoration: Mallus can also apparently restore any lost aspects of a person as upon resurrecting Damien, he regained his lost memories while part of the Legion of Doom. He also regained his magical powers, which were apparently improved to no longer require the Khushu Idol.
- Resurrection: Mallus' has the power to resurrect the dead. He resurrected Damien Darhk.
- Telepathic powers: Mallus has also displayed telepathic capabilities. So far he has shown...
- Illusion conjuration: He was able to cast illusions which were realistic. It made Sara believe that Mallus' demons were attacking her.
- Memory manipulation: He was able to manipulate Sara Lance's memories, so show her the painful memories she has repressed for years, enthralling her in submissive fear.
- Intimidation: Rip states that the Time Masters, were too frightened to even speak his name. Mallus was able to strike fear into the highly courageous and dangerous assassin Sara Lance, when she heard his voice in the very dark dimension he was imprisoned in. The Time Bureau are also terrified of him.
- Occult Knowledge: Mallus is skilled in spells such as a time based one in order to transport the Legends.
- Totems: Mallus is vulnerable to whomever wields one of six mystical totems of Water, Earth, Fire, Air and Spirit; the sixth is currently unknown. If he is even touched by one of the totem bearers, it burns him considerably.
- Possession resistance: Mallus can only possess someone who has been completely consumed by their rage and darkest fears. If they have not, they can resist his influence successfully.
- Dimensional imprisonment: Mallus is sealed off in his dimension, which serves as his prison. However, it does not stop his power and influence from reaching out.
- Mallus' influence on the timeline has been so far identified as random anachronisms throughout history; when Nate Heywood conducted a scan of the timeline, he determined that a series of anachronisms were directly linked to the fracturing of history caused by the final defeat of the Legion of Doom, but Mallus' anachronisms broke this pattern.
- Ray Palmer and Nate have noted that these divergent anachronisms have all had some connection to the Legends' own personal histories; Mallus' first role in an anachronism was linked to Ray Palmer's younger self, another involved Sir Henry Stein (Martin Stein's great-great-grandfather), and a later anachronism targeted the younger Stein, while one anachronism was peripherally linked to Mick Rory's father.
- When Sara Lance spoke directly to Mallus, he has expressed a personal interest in her for unspecified reasons, reinforcing the implication of his ties to the Legends.
- Mallus' claim that he would soon be free, indicates that he is currently imprisoned in the realm White Canary discovered him, solving the question as to why he must communicate with his followers through Nora Darhk.
- Mallus is very similar to Savitar in that they are both godlike villains, who are initially trapped in some sort of alternate dimension; influencing the outside world by possessing a certain individual (Nora Darhk and Alchemy, respectively), and are both the main antagonists of the third seasons of their respective shows; Legends of Tomorrow and The Flash. Also, Mallus exists simultaneously throughout all of time, which was Savitar's ultimate goal.
- Mallus' name is likely derived from the Latin word "Malus", which means, among other things, "evil", "bad", "wicked", "ill", "harmful" and "noxious".
- When Sara Lance asked Nora Darhk what voices she heard in her head from Mallus, Nora replied the number 6, which John Constantine points out is the number of the Biblical Beast from Christianity's Book of Revelation.
DC's Legends of Tomorrow
- "Aruba-Con" (mentioned)
- "Freakshow" (mentioned)
- "Return of the Mack" (voice; possessing Nora Darhk; divine power)
- "Helen Hunt" (divine power)
- "Beebo the God of War" (voice)
- "Daddy Darhkest" (voice; possessing Nora Darhk)