Mantis was the daughter of Gustav Brandt and Lua Nguyen. While a child, she was trained by the alien Priests of Pama, a sect of the Kree, who believed that she might become the "Celestial Madonna". She excelled in her martial arts studies, which landed her the name "Mantis". Being the protectors of the Cotati, the Priests of Pama enhanced her mind giving her telepathic abilities. On her 18th birthday, she was mindwiped and was given false memories of a childhood as an orphan in Vietnam, in order for her to experience a regular human life, which would be an aid for her to become a Celestial Madonna.
Swordsman & The Avengers
As an Avenger, Mantis battled the Troglodytes, and then later Doctor Strange as part of the Avengers/Defenders War. She, along with the Avengers, teamed up with Doctor Strange and the Defenders to fight Loki and Dormammu.
Mantis, Swordsman, Vision, and Scarlet Witch saved Thor, Iron Man, Captain America, and Black Panther after they were captured by the Collector. After that, the Avengers fought off the Zodiac Cartel when they tried to kill all New York citizens born between May 21 and June 21 (Geminis). She was reunited with her father Gustav Brandt, who was now a member of the Zodiac Cartel, under the name Libra. However, she had no memory of who he was. Libra retold the story of Mantis' birth and childhood, but Mantis wouldn't believe him. To make it worse, Swordsman believed the story and set off to find her uncle, Monsieur Khruul, the man who killed her mother. Mantis and the rest of the Avengers followed Swordsman, but when they arrived they found Swordsman strapped to a chair, having been tortured by Monsieur Khruul. When they found Monsieur Khruul a little while later, he had already been killed by the Star Stalker. After a brief battle with the Star Stalker, the Avengers returned home.
She became really close with the Vision during her time as an Avenger, which caused a lot of arguments between her, Swordsman, Vision, and the Scarlet Witch. However, they always got past it during times of trouble. Mantis later became a key player in the "Thanos War", fighting alongside the Avengers, Captain Marvel, and Drax the Destroyer to defeat Thanos and his quest to conquer Earth using the Cosmic Cube.
She neglected the Swordsman and his feelings for her, and pursued her interest for the Vision. However when she was revealed to be the Celestial Madonna, Kang the Conqueror threatened to kill her. It was Swordsman's heroic sacrifice that saved Mantis' life, and it was only when Swordsman was dying that she proclaimed her love for him. Three days following Swordsman's death, the Avengers buried him in the temple in Vietnam where Mantis grew up in. While at Vietnam, Mantis took the time to investigate on her mysterious past. However, after a few hours of investigating, she and the rest of the Avengers were taken by Kang to limbo. Kang sent the Legion of the Unliving to kill the Avengers, except for Mantis, whom he intended to bear his child. The Avengers, alongside Immortus, managed to defeat Kang and the Legion. Immediately afterward, Immortus offered Mantis and Vision a detailed retelling of their pasts, by sending them back in time as spectators of their own history. They agreed to do it, but it was done separately. Vision watched his past unfold by himself, while the rest of the Avengers went with Mantis, as they watched the origin of the Kree-Skrull war, the Cotati's exile into Earth, and how the Priests of Pama trained Mantis to become the Celestial Madonna.
Returning to Earth, Mantis discovered that she buried Swordsman in the garden where the eldest Cotati had lived, and that same Cotati had taken telepathic control over Swordsman's body. Mantis, now having accepted her fate as the Celestial Madonna, agreed to marry the Cotati. She had her marriage alongside the Vision and Scarlet Witch. Afterward, they left the Earth to mate.
However, it was only their spirits that left Earth. Their bodies remained on Earth, and would later be buried by the Priests of Pama. After conceiving the child with the Cotati spirit, Mantis' spirit returned to her body in Earth to bear the child. However, Mantis had to create a simulacrum, a body out of vegetation, in order for the embryo to live in a suitable womb. For months, Mantis carried the child, and when the child was born, they isolated themselves in a suburban house in Connecticut, where Mantis would raise the child. Not long after, the Cotati people decided to take the child from Mantis in order for it to develop its plant aspect. Feeling restless and unfulfilled, Mantis left her body, and her spirit went off into space seeking new adventures.
In space, Mantis discovered a plot by the Elders of the Universe to destroy Galactus using the Infinity Gems. She sought the aid of the Silver Surfer, who was also against the Elders at the time. During their campaign against the Elders, Mantis and Silver Surfer ended up forming a romantic bond. This was brought to the test when Mantis and Silver Surfer's former love interest Shalla-Bal were both captured by the Elders. The Elders forced Silver Surfer to give up the Infinity gems in his possession in order for them to release Mantis and Shalla-Bal. Silver Surfer ended up giving the Infinity gems, but the Elders tricked Silver Surfer, by flinging Mantis and Shalla-Bal's shared prison cell to space, where it would explode. Surfer managed to save Shalla-Bal, but Mantis was caught in the explosion.
Mantis was not killed in the explosion. Instead, fragments of her essence were spread out all across the universe. One specific fragment of her essence awoke in Earth, not remembering anything since she left the Avengers and Earth. She sought the help of the West Coast Avengers, where she was reunited with old allies such as Vision, Scarlet Witch, and Hawkeye. She joined the team not long after half of its team members left, and helped them take down Voice, and even took part in the Evolutionary War. Not long after, the team helped her investigate her recent past to figure out what had happened to her. The team visited the Priests of Pama temple in Vietnam, and that is where they found the Cotati spirit of Swordsman. The Cotati spirit attacked Mantis, and killed that simulacrum form of her's, thus sending her spirit back into her original body that she left behind on Earth that long ago. Mantis, with her memories restored now, thanked the West Coast Avengers, and requested that she remain to reflect on recent events.
A couple of months later, another fragment of Mantis arrived in New York City, and encountered the Fantastic Four as they were dealing with the effects of Inferno. This fragment of Mantis, who had lost her powers to travel in space, requested the Fantastic Four to help her find her child. The Fantastic Four agreed to help, but just then Kang the Conqueror returned seeking vengeance on Mantis. Kang kidnapped Mantis and flew to Mount Diablo in California using his spaceship. The Fantastic Four pursued and battled Kang in Mount Diablo. While everybody was busy, Necrodamus, who had been spectating the fight for awhile, quietly stole Mantis away from Kang, and went back to New York, where he would sacrifice her just as the planets aligned so that he could use her life force to gain rewards from the gods of evil. This led to the Fantastic Four teaming up with Kang to defeat Necrodamus. Ms. Marvel, a member of the Fantastic Four at the time, hatched a plan to move Mercury ever so slightly out of position in order for that planetary alignment to fail. Kang and the Human Torch were successful in moving Saturn, but when Mantis awoke neither of them had returned.
A while later, Silver Surfer returned to Earth carrying Human Torch, for Kang had betrayed him and left him to die in space. After a brief conversation between Mantis and Silver Surfer, Kang reappeared but this time with the High Council of the Cotati, where they discouraged Mantis from searching for her son because they specifically wanted the Cotati to raise them. They debated back and forth, but since Mantis wouldn't budge, Kang released the Priests of Pama to attack Mantis, Silver Surfer, and the Fantastic Four. During the fighting, Silver Surfer knocked Kang out, but the Cotati fled into a realm of pure thought. When the fighting was over, Mantis said her final goodbye to Silver Surfer, as her spirit once again left her body.
Much much later, the Silver Surfer encountered another fragment of Mantis on the planet of Verdant. To this fragment of Mantis' surprise, the Silver Surfer was once again serving Galactus, and he was on the search for a planet for Galactus to devour. She pleaded for Norrin not to lead Galactus there, and she succeeded in convincing him to look for another planet. The two found a neighboring planet that wasn't as rich with life as Verdant, but they went to Galactus to bring him the news anyway. However, when Galactus arrived in that solar system, he discovered Verdant and all its inhabited life, so he chose to devour that instead. Mantis' soul was crushed, and so she departed, telling Silver Surfer that they may only be allies when he wasn't serving Galactus.
Over time, these fragments (or "ghosts") of Mantis would fade from the memory of those she would encounter.
Mantis' fragments later became more substantial, now representing the five sides to herself - the Freak, the Mother, the Woman, the Adept, and the Avenger. All living on Earth, soon to become one whole person again.
Thanos hastened this process by tracking down all the five Mantises and killing them, with each one's essence moving on to the next one until they formed the whole. Thanos had attempted to kill her, for a star foretelling the rise of the new Celestial Messiah was near, had appeared. Thanos and Mantis engaged in battle, with Mantis' fellow Avengers watched, and it was while they were battling, Mantis realized Thanos was after her son. The battle was a draw and Thanos teleported away. Mantis requested the aid of the Avengers and Haywire to travel with her to the homeworld of the Cotati to protect her son, and they accepted.
On the way there, Mantis filled the Avengers in on her journey since she left the Avengers half a decade ago, and the Avengers brought her up to speed on what has transpired in their group since. Mantis found out of Vision and Scarlet Witch's separation and the loss of their children. Later, she and Vision were alone and were talking about their feelings for one another, so she made her move and the two had intercourse.
They soon arrived on the Cotati homeworld, where they were reunited with the reanimated corpse of the Swordsman and Mantis' now eighteen-year-old son, Sequoia. Sequoia wasn't accepting of his mother at first, and so Mantis spent most of her time there trying to reach out to him. The next night, while Vision and Mantis were having sex, Sequoia was kidnapped, but the assailant was unknown. They knew it wasn't Thanos, for his means were more violent and upfront than a stealth kidnapping. Angry with the humans, the Cotati then attacked Mantis, the Avengers, and Haywire, which forced them to leave the planet hastily.
Mantis was able to telepathically locate where Sequoia was. Sequoia was taken to the Rot, a giant void of nothingness that continued to grow in a patch of space. They set the coordinates, but Mantis said she'd have to go to Eternity for help. Vision volunteered to go with her, and the two traveled through space. However, when they got to Eternity, he denied their request to help them. Immediately after, Thanos surprise attacked the two and captured them. They were brought to his ship where they found Sequoia and an unknown pirate captured. Thanos took Mantis to a torture room to execute her mentally, but her power was too strong. Thanos decided to let her live instead and to focus all his energy on Sequoia. A futile effort, as Sequoia was more powerful than his mother, so he defeated Thanos and rescued his mother. Mantis, Sequoia, and the Vision were ready for escape, but Lady Death revealed to them they were now stuck in the Rot, doomed to die.
Mantis, Thanos, Sequoia, the Avengers, and everyone else thought of ways to get out, while Mantis and Sequoia made a temporary force field around the ship to give them more time. They tried numerous plans, but when Death revealed that the Rot was her "offspring" with Thanos, Thanos knew what had to be done. He and Death left the ship, and destroyed the Rot, releasing anyone who had been trapped in it earlier. In the end, even though she wished that he would've joined her, she had to say goodbye to her son for he had his newly appointed duty of being the Celestial Messiah. She also had to part ways with the Vision, for she was the Celestial Madonna, a goddess of life, and he was an android, incapable of giving life. She is humanity, while he is but an android.
Mantis later went to space where she foresaw a vision about the Annihilation Wave. She let herself be imprisoned so she could wait for the arrival of Star-Lord and help him on his mission. She played a big role in a waging guerrilla warfare against the Phalanx, often saving Quill and their teammates from danger and even accepting that she would likely die in the process. She was severely injured by an Ultron-formed Phalanx, but barely survived and was carried to safety by Star-Lord and their remaining teammate's Bug and Rocket Raccoon.
Guardians of the Galaxy
She eventually recovered from her injuries and agreed to help Quill in forming the Guardians of the Galaxy by psychically influencing Drax, Phyla-Vell, Gamora, and a newly resurrected Adam Warlock to join their struggling attempts to reestablish the galaxy's balance and order after the destruction from the Annihilation waves. Mantis recorded all of the team's actions and achievements and attempted to help a newly-discovered, reality-displaced Vance Astro with his amnesia. She and Astro were assaulted by Vance's previous teammate, Starhawk and were subsequently left with the mystery as to why he attacked them in the first place. When the team was later threatened by paranoia and superstition resulting from a potential infiltration by Skrulls, Mantis opposed Starlord in their mental violations against their teammates. The team still eventually managed to incapacitate Starhawk, but the damage to the team had been done, and they disbanded from an inability to trust each other any longer.
As the War of Kings came to a close, it seemed as though Magus had killed several members of the Guardians of Galaxy, including Mantis. However, it was later revealed to be a trick in order to kidnap the supposedly dead Guardians and escape the war. Mantis and her teammates were eventually rescued by the other Guardians of the Galaxy and joined them to fight the encroaching Cancerverse.
When her son Quoi, attempted to conquer the Earth, she tried to dissuade him from across the galaxy through a shared psychic link. He destroyed the link rather than listen to her continued pleas for peace. 
Mantis always behaves in an assertive manner, feeling confident in herself and her powers. Initially she was somewhat arrogant at times, telling Swordsman that he was "too weak" for her; however, she repented after his death. She is highly intelligent, with deductive skills rivaling those of Vision's; in his own words, she has "a remarkable mind".
As a result of her upbringing at the Temple, she has an idiosyncratic holistic worldview similar to real-life Eastern philosophy and sees herself as a part of a greater whole. For this reason, she always refers to herself in the third person as "this one", "she", and occasionally "Mantis" instead of "I", which is apparently a tradition among the Priests of Pama (the Cotati Elder, who spent a significant part of his life at the Temple, also speaks like that). This speech pattern is a conscious choice: at one point, she almost said "me", and then corrected herself. At another point, when Silver Surfer asked her to stop speaking in the third person, she retorted by making him admit he was romantically interested in her, and refused to comply.
Telepathy: Mantis has repeatedly demonstrated telepathy as well as a variety of other mental powers. She has performed feats as sophisticated as constructing a small telesensual schematic of a Phalanx spire for all of her teammates to see.
Empathy This enables her to sense the emotions of others, which she feels as psychic "vibrations" which she also uses to communicate with the plant-like Cotati.
Astral Projection: To travel in space, Mantis projects her astral form from her body, allowing her to travel interplanetary distances. She'd then recreate a body for herself out of the destination planet’s local vegetation. Her fighting skills remain intact, and her empathic abilities' heightened to a superhuman degree and extended to the planet’s flora and biosphere.
Chlorokinesis: She also possesses the ability to control the vegetation within her vicinity. Mantis was able to accelerate her teammate Groot's cellular growth rate and even alter his sap to make it flammable.
Pyrokinesis: Mantis burned her teammate Groot's internal sap with her mental powers, immediately lighting him on fire from the inside.
Precognition: Throughout the Annihilation Conquest series she proved to possess precognition. She was able to foresee almost all the events that would occur during her mission with Star-Lord (Peter Quill) and their teammates. She eventually explained that if she had told him that she knew that some of their teammates would perish on their mission, he would never have embarked on it and taken them with him and she was even accepting that she would perish as well.
Enhanced Durability: Mantis has physically enhanced durability as well as immunity to mental and metaphysical assaults. This was proved when an Ultron-controlled Adam Warlock teleported to her location with her teammates and struck her in the head. She survived but was left comatose.
Self-Healing: Mantis can will herself to heal.
Master Martial Artist: Mantis has extraordinary ability in the martial arts that have been developed and perfected over thousands of years. These fighting methods place particular emphasis on the manipulation of pressure points and nerve endings on the bodies of one's opponents. So, by knowing the right areas of the body to strike, Mantis can stun even a being as powerful as Thor even though she herself has no superhuman strength.
Nervous System Control: Thanks to her training, Mantis has "complete control" over her body. With her sheer force of will, she's capable of willing herself to recuperate quickly after being injured.
- After the Celestial Madonna storyline concluded and Steve Englehart started working on DC's Justice League of America title, he brought Mantis into the JLA's storyline, calling her by the alias Willow. Despite the name change, her dialogue made it as clear as copyright would allow that she was 616's Mantis, living on DC's Earth as a way of keeping her infant child out of the reach of his enemies. Mantis later turned up in Eclipse Comics' Scorpio Rose, again written by Englehart, and this time calling herself Lorelei. Both aliases are included in Mantis' entry in Official Handbook of the Marvel Universe: Avengers 2005 #1.
- Mantis was one of the characters featured in the series of Marvel Value Stamps issued in the 1970's.
- Besides Mantis there have been other candidates who could have become the Celestial Madonna: Moondragon was also trained on Titan to become the Celestial Madonna, but failed at being a perfect human. When Shanna was under the control of the Empyre, Ventri thought that Shanna had the potential to become the second Celestial Madonna.
- 140 appearance(s) of Mantis (Brandt) (Earth-616)
- 46 minor appearance(s) of Mantis (Brandt) (Earth-616)
- 39 mention(s) of Mantis (Brandt) (Earth-616)
- 110 image(s) of Mantis (Brandt) (Earth-616)
- 14 quotation(s) by or about Mantis (Brandt) (Earth-616)