Margaret has long, slightly wavy, indigo hair and wears a short-sleeved, long black dress while imprisoned.
Elizabeth points out that she greatly admires Margaret's gentleness and kindness. Like Elizabeth, she believes that the Seven Deadly Sins are the greatest group of knights specially assembled by her father, and that the Holy Knights are the traitors attempting to overthrow the kingdom. However, Margaret appears to be cowardly as the Vivian claimed that she choose to be in prison rather than helping her father like her younger sisters Elizabeth and Veronica. However, it was proved untrue as it was revealed that Margaret was being hold hostage by a creature called Chimera.
In her childhood, Margaret made Little Gil to promise her to protect her at all times as a knight should to his lady. At some point in time, Margaret gave her ear ring to Elizabeth on her 16th birthday, and when the Holy Knights overthrow her father King Liones, she was forced to be imprisoned. During the Kingdom Founding Day festival, Margaret overseen Gilthunder's uncle, Dreyfus and his partner Hendrickson poisoning Gilthunder's father and Great Holy Knight Zaratras, and killed him to her honor. Margaret went and told Gilthunder everything about Zaratras to his shock, until their were found out by Vivian who took Margaret hostage by using a Chimera to keep Gilthunder in line and serve the Holy Knight.
While in imprisonment, Gilthunder came to visit Margaret and report to her that her sister, Veronica, death, to which the latter grew anger at Gilthunder, believing that the Holy Knights were the one who killed her sister. Gilthunder told Margaret that it was the Seven Deadly Sins to which the latter refuse to believe since her father form the group and the Holy Knights are the true traitors and curse Gilthunder for working for them. While imprison, she hear Elizabeth calling for her which she respond. Elizabeth found Margaret's cell and told her about Veronica and that she was blaming herself for her death. As Margaret was trying to comfort Elizabeth, the Holy Knight that abducted Elizabeth showed up. She wondered how Elizabeth got out of her cell and also that Margaret is in the cell by her own free will as the latter look away in shame. Elizabeth did not believe that and as the Holy Knight was about to get her, Hawk hit her and protected Elizabeth. As Vivian teleported Hawk away and knocked out Elizabeth, the Holy Knight opened Margaret's cell, telling she will grant Elizabeth's wish and that Margaret is free, as long as she have the courage to escape.
Leaving her cell, Margaret heads outside to see Gilthunder battling his hero Meliodas and begged him to stop while running towards the chaotic battle. When Meliodas used Divine Slayer in Margaret's direction, it turned out that he was aiming for the mysterious creature following the princess saving her life, resulting to Gilthunder to turn against Hendrickson almost immediately. Margaret stood there, lost at the current event and the monster that was close to her. As Meliodas clean himself and walk toward Margaret, the latter ask how Meliodas knew about the monster, Meliodas explain that he realize something was off when they met in Forest of White Dreams and realize what is wrong with Margaret a few moments ago. Meliodas explain that Gilthunder would never compromise his sense of justice if hist life was in the line, and realize that Margaret was in danger the whole time. Margaret started to cry and thanks Meliodas for saving them. Vivian ask what made him realize the event, which Meliodas explain that the creed and the way Gilthunder said he was stronger than the Deadly Sins was some kind of code or charm if he was ever in trouble which Meliodas give him ten years ago, and when Gilthunder said those word back in the White Dream, he knew he was being watched and someone being taken hostage. After the a long battle, Gilthunder stab Hendrickson and unleash his full power of his Thunderbolt and defeated him and reunion with Margaret.
As all the Holy Knights of the kingdom surround Merlin's old castle to bar Hendrickson's escape while Sins battled him, Margaret and Hawk stayed close to Elizabeth's side as the wounded princess is medically treated by a Holy Knight with healing power. When Hendrickson appeared and started to kill the Holy Knights with ease, Margaret wondered why Hendrickson is so interested in Elizabeth which the latter stood up to Margaret shock. As the battle rage on, one of Elizabeth friends, Hawk, was killed during the battle which awake a large light beam that came from Elizabeth. When Gilthunder believe the light to be the after life, Margaret quickly explain that it wasn't as Elizabeth unleash her true power while revealing that Elizabeth has been unknowable healed many people in her life time. After Meliodas killed and finish Hendrikcsen, Baltra reappeared and regain ordered within the kingdom alongside with Merlin. As the Holy Knights knee for Baltra, the king thanked Gilthunder for protecting Margaret while he was unable to which led to Gilthunder to request a private chat with the king which Baltra accepted.
Post-Kingdom Infiltration arc
While Elizabeth was resting in bed due to not healing herself during the battle, Margaret went to Elizabeth room to check up on her which it was where she met Merlin and when Meliodas step out of the room with a grin which made some of them worried that he did something weird, until it was revealed that Elizabeth is up and healed for unknown reason. Margaret was overjoy to see Elizabeth standing again, but wondered why she is moving again. The next day, Gilthunder bid farewell to Margaret who the two were about to kiss as Gilthunder was quitting the Holy Knights to become a wander due to his sins, even if it was just an act.
Margaret possesses no superhuman abilities or equipment.
Elizabeth loves her adopted sister very much and admires her kindness and gentleness. Margaret appears to loves her as well and gave her, her ear ring.
Margaret and Veronica have slightly different views on the Holy Knight and the Seven Deadly Sins, but despite this, Margaret cares greatly for Veronica and grew extremely upset and angry when she knew about her death.
Gilthunder acted as Margaret personal knight during their childhood. However, Margaret began despise the Holy Knights, including Gilthunder, for betraying the kingdom and overthrowing her father. At the same time, Gilthunder remains mindful and considerate of her. However, after finding out Gilthunder true action and what Meliodas told her, Margaret soon forgiven Gilthunder. It is hinted that Margaret harbored romantic feelings toward Gilthunder during their childhood and still holds them to this day.
- According to the second databook(s):
- Special ability: Dancing
- Hobbies: Drinking tea
- Weak Point: Gil
- Dream/Hope: Being Gil’s wife
- Regrets: Nothing
- The most embarrassing thing in her life: Showing herself in an embarrassing state in front of Gil
- What she wants the most right now: Peaceful days with Gil