Mallus

"I've been expecting you, Sara Lance. Soon, you will gaze upon my true face. Soon, you will inhabit my world."

- Mallus to Sara Lance, planning to possess her. "For the last five years, I've been chasing a phantom. A name whispered across time and in every language: Mallus. An evil so ancient and powerful that the Time Masters dared not speak his name."

- Rip Hunter describing Mallus to the Legends.

"I am so much more than a god!"

- Mallus after finally escaping his dimensional imprisonment. Mallus is the main antagonist in the third season of the Arrowverse series, DC's Legends of Tomorrow. He is a powerful, evil and ancient time demon who was sealed inside another dimension due to his fearsome presence and desire to wreak havoc throughout all of time, who now returns to claim vengeance for his long imprisonment.

He is voiced by John Noble, who also portrayed Unicron in Transformers: Prime, Walternate in Fringe, Henry Parrish in Sleepy Hollow and Scarecrow in Batman: Arkham Knight. While possessing Nora Darhk and Sara Lance, he is portrayed by Courtney Ford and Caity Lotz.

Overview
An ancient, evil and immensely powerful demonic entity, Mallus was known to time-travelers as a great enemy whose very existence scares the most intimidating and brave figures in history, including the Time Masters. In ancient times, Mallus battled in a war against the original totem-bearers from the tribes of Zambesi, with his only allies being the tribe who presented the Death Totem. Afterwards, Mallus was imprisoned in a barren dimension made out of time and located between worlds. A large cult known as the Order of the Shrouded Compass, who came to be aware of Mallus' power, started worshiping him as a pagan god and follow his every will.

After the Legends broke time and indirectly created anachronisms, Mallus became a threat to all of existence once again as he then recruited more loyal followers, including Nora Darhk, Kuasa, Damien Darhk and Grodd, and had them continuously corrupt and destroy the timeline so that he can finally escape from his prison and subject the world to an "unendurable pain" against humanity for his incarceration. He also has them seeking out the Totems as they appear to be the only magical artifacts that have a chance at defeating him.

During the course of this plan, Kuasa and Damien began to have second thoughts, with Kuasa later siding with her grandmother, only to have Mallus/Nora kill her by stealing the Water Totem; and Damien to side with Legends after realizing that releasing the demon will mean that he loses his daughter. However, after history was completely destroyed, Mallus successfully consumed Nora's body and assumed his true form upon escaping his dimension.

Personality
"You will not look upon my true form and live. While you are hopelessly mortal, I am a god!"

- Mallus' egotism as he views himself as a god.

Though he currently hasn't appeared in physical form yet, whilst possessing Nora Darhk, Mallus has shown to be a sinister and malevolent figure whose very existence even scared the Time Masters. He is also egotistical, arrogant and narcissistic as he claims to be a living god while he views everyone as "hopelessly mortal". When Sara Lance accidentally entered the very dimension he was imprisoned in, he vowed to her that once he is freed from his time prison, he will make her entire world know "unendurable pain", showing that he appears to be highly vindictive.

Being a demon with a disregard for humanity, Mallus is highly sadistic, cold, immoral, manipulative and completely cruel, as he enjoyed tormenting Sara Lance in an attempt to possess her, and he enjoyed scaring Ray Palmer and Zari Tomaz while torturing a possessed young Nora Darhk. After fully possessing Sara with the Death Totem, Mallus was cold and utterly remorseless when he fought and brutally tortured the Legends both physically and psychologically. Upon meeting her in his dimension, Mallus appears to take an interest in Sara Lance as she appeared to be a potential candidate to the next wielder of the Death Totem, thus desiring to possess like Nora and also sway her over to his side to fight for him.

Mallus also does not respond well to traitors as he ruthlessly removed the Water Totem from Kuasa, effectively killing her instantly. In a more similar case, Mallus also shows no regard for his own followers as he appeared to have no regard in consuming and killing his most loyal follower Nora to assume his true form. He also never valued their families as he angrily believed that he gave Kuasa "real power", unable to accept that Kuasa valued her own family over destroying time, which also cost Kuasa her life.

Mallus, however, was not without fear. Even though he was unfazed by John Constantine, the Time Bureau, Rip Hunter and the Legends' threats or attempts to subdue his seemingly unlimited power, he has shown to be physically afraid of the Zambesi totems as they appear to be the only things that can harm him. His fear of the totems has left him desperate to assemble all six of them before the Legends do and would become quite ill-tempered whenever they keep collecting them.

Powers and abilities
"If you cannot defeat me in this vessel, how will you stop me once I've assumed my true form?"

- Mallus gloating his immense power as he overpowers Kid-Flash, Steel and Vixen while possessing Nora.

Powers

 * Demonic Physiology: Due to being an immensely powerful, fearsome and enormous devil-like demon, Mallus possesses tremendous amounts of supernatural power. So far he has shown the following powers:
 * Immortality (possibly): Mallus claims to be a god in comparison to individuals like Rip Hunter, suggesting that he is possibly immortal. However, it is currently unconfirmed.
 * Immunity: Mallus has shown that he is completely immune to any form of exorcism, including John Constantine's rituals and magic.
 * Demonic Possession: Mallus has shown that he has been able to speak through other individuals, as demonstrated when speaking to Rip Hunter through Nora Darhk. It is later shown that he has possessed her before as a child.
 * Power Bestowal: Mallus is able to grant Damien and Nora Darhk powers similar to those obtained through the Khushu Idol, and including 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 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 Darhk the same ability.
 * Superhuman Durability: Mallus can grant Nora the ability to take massive hits with no harm brought to her.
 * Superhuman Strength: Mallus made Nora significantly strong, enough to use her nails to easily scratch on a table without any signs of slowing down, strain or fatigue.
 * Telekinesis: Mallus has demonstrated that he can grant Nora the power of telekinesis, as he demonstrated while possessing her.
 * Immobilization: Damien Darhk has shown, on numerous occasions, to use his telekinetic powers to halt all the movements of multiple people at once.
 * Electrokinesis: Mallus can grant Nora the power to control electrical energy, as he allowed her to drain Kid-Flash of his electricity and fire it back at him.
 * Restoration: Mallus has demonstrated that he can also restore other individuals' memories, as shown when a recently resurrected Damien Darhk remembered Rip Hunter, the Legends and his time when part of the Legion of Doom. He also restored Damien and Kuasa's magic to an extent that they no longer required his Khushu Idol and her Water Totem to use them.
 * Biological Manipulation: Mallus made dark colored goo (most likely blood) appear from Nora's mouth whilst possessing her.
 * Resurrection: Mallus has the power to resurrect the dead, as he resurrected Damien Darhk.
 * Telepathy: Mallus has demonstrated that he has telepathic capabilities, as when he used this power to whisper in Sara Lance's mind to scare her.
 * Illusion Conjuration: Mallus has shown that he can project illusions into people's minds, including when he made Sara believe that a demon was attacking her out of a hallway wall. He also used this power to pose as Sara when she was the Canary in order to manipulate her.
 * Memory Manipulation: Mallus has projected disturbing memories into Sara's mind to try and ensure that she is consumed by fear.
 * Flight: After finally revealing his true form, Mallus has shown his capabilities at flying thanks to his enormous wings.

Abilities

 * Intimidation: Rip states that the Time Masters, who were once a fearless and arrogant organization, were too frightened to even speak his name. Mallus was even 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 apparently terrified of him as well, even though they discard his existence. Later, the Legends and Damien Darhk could only watch in absolute terror as he revealed his true form.
 * Occult Knowledge: Mallus is skilled in spells such when he used a time-based spell in order to transport the Legends.

Weaknesses

 * Totems: Mallus appears to be vulnerable to whomever wields one of six mystical totems of Water, Earth, Fire, Air, Spirit and Death. 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 currently sealed off in a mysterious dimension, which serves as his prison. However, it does not stop his power and influence from reaching out into the Multiverse.

Season 3

 * "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 and hand)
 * "Daddy Darhkest" (voice; possessing young Nora Darhk)
 * "Here I Go Again" (mentioned)
 * "The Curse of the Earth Totem" (possessing Nora Darhk)
 * "No Country for Old Dads" (possessing Nora Darhk)
 * "Amazing Grace"  (mentioned)
 * "Necromancing the Stone"  (voice; possessing Sara Lance)
 * "I, Ava" (voice; possessing Nora Darhk)
 * "Guest Starring John Noble"

Quotes
"Sara Lance. (Sara: Who's there? Who are you? What is this place?) I am Mallus! Soon, I will be free and your world will know unendurable pain!"

- Mallus introducing himself to Sara Lance.

"Sara. Sara. You're getting closer. They can't reach you. Only I can."

- Mallus intimidating Sara Lance.

"The girl is empty. Long before you arrived, she was MINE!"

- Mallus possessing Nora Darhk again before attacking Ray Palmer and Zari Tomaz.

"The first totem bearers imprisoned a great evil and if he breaks free…He cannot enter your world, but this is the world between worlds. Time does not exist here and time is his cage. And the further time is broken, the closer the demon comes to breaking free. And if you do not stop them [Mallus' followers], all of time is at risk."

- Amaya's ancestor explaining Mallus' origins.

"Sara Lance is lost to you. I am…death!"

- Mallus tells Amaya and Mick after fully possessing Sara Lance.

"She can't hear you. (chuckles) You have always secretly feared you're a monster. And now, a monster is what you've become!"

- Mallus taunting Sara Lance about her fears of believing she's a monster.

"Finally, I am free!"

- Mallus as he consumes Nora Darhk's body to assume his true form and finally escape his prison.

Trivia

 * Mallus' name is most likely derived from the Latin word "Malus", which literally means, among other definitions, "evil", "bad", "wicked", "ill", "harmful" and "noxious". This is most likely to represent his personality.
 * When Sara Lance asked Nora what voices Mallus whispers in her head, Nora stated "the number 6", which John Constantine points out is the number of the Beast from Judeo-Christian's Revelations as well as the Biblical Rapture and Armageddon Prophecies.
 * Mallus is currently the only main antagonist in the Arrowverse live action series' who is an original character. Initially, he was alongside Cayden James, the main antagonist in the sixth season of Arrow, as being an original character and main villain, until it was revealed that Cayden is being manipulated by Richard Dragon.
 * He also appears to be the first main villain of the Arrowverse that is an actual demon, whereas previous main villains are usually assassins, crime lords, speedsters, sorcerers, meta-humans and aliens.
 * Mallus is currently the only main antagonist of DC's Legends of Tomorrow that has not previously fought Barry or Oliver.
 * Mallus appears to be one of the darkest main antagonists in the Arrowverse.
 * Although an apparently original character, Mallus appears to be very similar to the villain Savitar as they are both worshiped as gods; both of them egotistically view themselves as actual deities; both of them are trapped in alternate dimensions outside of the known world (A currently unidentified dimension and the Speed Force); they both speak to their enemies through their subjects (Nora Darhk and Doctor Alchemy); and both of them are the main antagonists in the third seasons of their respective shows (DC's Legends of Tomorrow and The Flash).
 * Interestingly, some viewers theorize that "Mallus" is likely an alias and that he possibly has a supposed true identity, with a list of potential suspects including Gary Green, Ava Sharpe, Director Wilbur Bennett, Leo Snart/Citizen Cold, Zari Tomaz, Savitar and Vandal Savage. However, this theory has been redacted since Mallus's true form was revealed.
 * According to EP Marc Guggenheim, Mallus will be a full CGI character once he makes his physical debut.