Felix Argyle (フェリックス・アーガイル), commonly known as Ferris (フェリス), is Crusch Karsten's knight. Debuting in Arc 3, he played a rather vital role as Crusch's knight and supported Subaru in his fight against the Hakugei and Sin Archbishop of Sloth. Though not present in the following 4th Arc, he reappeared in Arc 5 and yet again played a vital role for Crusch's character development.
Ferris has flax colored hair and yellow eyes. His casual wear consists of a blue collar with a ribbon, a blue dress, black tights, blue leggings, blue shoes, white arm covers, and a blue scarf tied around his right arm.
Ferris' cat like appendages are a result of his ancestors having Demi Human blood and because of this, he was mistreated by his parents. The white and blue ribbons that he wears in his hair are a gift from Crusch and he always wears them no matter what he's wearing.
Ferris usually refers to himself in third person, calling himself Ferri-chan (フェリちゃん), though he will refer to himself as Ferris, Felix, or with female pronouns depending on the situation. He is absolutely loyal to Crusch and will do anything she says, however he will oppose her if needed. He also enjoys teasing other people, especially those that are surprised that he's male, using cutesy language and gestures to agitate them.
Although he hides it through his actions and words, Ferris has a severe view on death and values due to his job as a healer, leading him to hold those who no longer have any will to live in contempt from the bottom of his heart. He also hates weaklings because of his complex, causing him to hate Subaru for a while, however he lets go of his feelings against him after seeing his actions during the battle against the Hakugei.
Ferris can get emotional when it comes to Crusch, such as the time when she was infected by Capella's dragon blood, becoming visibly stressed by her poor condition and even going as far as to demand to see a captured Sirius so he could torture her to gain information on how to cure her. He is constantly thankful for Crusch and everything that she's done for him in her life.
From the moment Ferris was born, he had cat like appendages due to his ancestors having Demi Human blood, causing his parents to mistreat him as they suspected an affair. He was locked in the basement of the Argyle Mansion for the first nine years of his life and was barely cared for. When Crusch found him, she described him as "a fragile boy who was painfully thin, was black from being covered in dirt and filth, and couldn't talk properly". He was subsequently taken to the Karsten Mansion to be cared for and made Crusch attendant while his parents lost what little standing they had with the Karsten family, leading to their decline.
In the following years to come Ferris would establish a strong sense of loyalty and devotion towards Crusch for taking him from the hell that was his life before and base part of his new identity on that relationship. He also came to befriend Fourier Lugnica a little while after the prince met Crusch. Together 3 would get into all kinds of mischief that defined much of their friendship.
At age 18, Ferris would join the Royal Guard under recommendations from Fourier and Royal Institute of Healing. Although he wanted to be of better use to Crusch, Ferris at first was not very comfortable in being the elite group for several reasons, he stood out due to his odd features marking him as a demi-human, his preference for wearing women's clothing, his own lacking combat abilities and lastly dissatisfaction of his unusual and sudden appointment despite all that from the other knights. However, on the first day, he also came to be acquainted with Reinhard van Astrea and Julius Juukulius which would be the first step in breaking the wall between Ferris and his new environment. Through his good relationship with both of them and the subtle opportunities to display his worth crafty granted by Marcos Gildark, Ferris would come to earn the respect of the other knights for saving their lives with his magic. This would come to give him a sense of his abilities and place there.
In the last month of his probationary period in the Royal Guard, before he became a permanent member, dark rumors surrounding his old family would reach his ears via Fourier. Learning that Crusch had gone to investigate them, Ferris together with Fourier and Julius would rush back to the Karsten estate to learn the truth of the situation. After their arrival, things would take a turn for worse when they learn that Crusch had been captured and her men were engaged an with an undead army outside the Argyle household. Ferris would also receive a message from his father that would demand he come to Argyle estate alone in exchange for saving Crusch. Returning to Argyle mansion for the first time in nearly a decade Ferris would confront his father and a maid named Hannah who he felt a familiar connection to. Following a cold reunion, Ferris would acquiesce to his father's demand to revive his mother with the Argyle's family ancient spell. However, when Ferris was brought to the master bedroom, and examined his mother's corpse he would come to the shocking conclusion that she was murdered due to the numerous and frenetic stab wounds in her body, partially thanks to Biehn's meticulous preservation. After a tense argument between Ferris and Biehn to which the later would lose his composure admit his guilt in the matter. Eventually realizing any further discussion was pointless Ferris revived the woman. The spell, however, ended up being a partial failure as despite his mother seemingly coming back with some part of her personality. Moreover, the now undead mother would kill Biehn as they embraced then crumbled into ash a moment. Hannah would then reveal to Ferris where Crusch was being held and that she had already freed her from her bonds. Just as Ferris raced out of the room, he would hear the locking and smoke coming from the room. Despite his protest, Hannah would not open the door choosing to die along with her master and mistress. The event marked a scar on Ferris' heart and where he developed deep hate for those who easily gave up their lives. He would meet Crusch and Julius in the foyer of the manor, relieve but utterly distraught by the whole event and escape the burning building with them.
After the incident, Fourier would collapse from a mysterious illness and Ferris would spend a year looking after him. Desperate and frustrated at the lack of progress Ferris would consider using the "Immortal King's Sacrament" to revive him after death but Fourier would forbid it and wanting to be allowed to die on his own terms if that was the case. They share a somber heart to heart moment and Fourier would pass away a couple of days later. On that same day, Ferris would take his oath of knighthood to Crusch to support her and Fourier's memory.
Divine Protection (加護 Kago): Ferris has the Divine Protection of Water (水の加護 Mizu no Kago), which makes him highly skilled at Water Magic.
Magic User: Ferris has extraordinary power and talent with water magic thanks to the combination of his bloodline and Divine Protection.
- Healing Magic: Ferris summons water mana through a person's body, a water mage could stimulate a patient's natural healing capabilities to speed up recoveries. Healing magic could help restore an injured body or cure a target of any ailment they might have within an instant. That being said, healing magic could only treat physical wounds and ailments whilst having no affect on mental afflictions. The skill, talent, and raw power of the mage using healing magic naturally affected the effectiveness of the treatment. Ferris was a healing prodigy who was considered to the greatest healer in the Kingdom if not the world. earning him the alias of Blue (青 Ao). He could, with little effort, instantly bring someone back to perfect health from the brink of death, even a gravely wounded person could be completely healed by Ferris without so much as a scar to show. Ferris could even seamlessly reattach lost limbs such as when he reattached Crusch's forearm after it had been cleanly severed by Regulus of Greed. There were however a couple of known afflictions that not even Ferris could heal including the illness that felled the entire Lugnican Royal Family and the infection caused by Capella of Lust's corrupted blood. Additionally, the target of Felix's healing magic needed to still have an ember of life within them for him to be able to save them, as even someone who had only recently passed away could not be rejuvenated by Ferris. He can make their body go out of control, enabling him to do things such as using their body like a puppet or destroying the circulatory system of their gates from inside. He can also die and heal himself to perfect condition, as shown during the battle against Petelgeuse, however it is unknown how many times he can do this.
- The Sacrament of the Immortal King (不死王の秘蹟 Fushiou no Hiseki): An ancient and powerful water magic spell invented by a Witch eons ago who used the power to enthral the world. It allowed the user to resurrect a person and restore them to how they were during their life. After the Witch's death a majority of the ritual was forgotten, the effect of the magic depends on the skill of the user and how much they understand about this magic otherwise they will only be able to resurrect people as zombies mindless. The zombies created by the spell were completely loyal to their reanimator and anyone who the reanimator gave command rights to. The amount of zombies possible to reanimate was unknown, although it was at least over a hundred. Very few people were capable of using the spell on any level, namely members of the House of Argyle including Felix and his father Biehn Argyle. Felix himself learned the spell from his family's magical tomes when his father tried to coerce him into resurrecting his wife. However, even though Ferris was able to restore a vestige of life into her body temporarily, Biehn's wife quickly broke down into dust.
Pseudo-Immortality: One way Ferris' body differs from most humans and demi-humans is his extraordinary connection with Water Mana imbue it with strong passive effect in which results in rapid cellular regeneration. With this in effect, it means he can recover from any fatal wound that doesn't kill him outright. However, in exchange it further weakens his ability to fight.
Demi-Human Traits: Due to the demi-human blood flowing through his veins, Ferris sensory organs were significantly enhanced past the limitations displayed by most humans. His cat-like ears in particular were able to detect the slightest change in his surroundings to the point that he could tell when someone turned to look at him. Because of his excellent hearing, he could always tell when someone was approaching him, with the exception of Reinhard van Astrea.
Equipment: Ferris owns a short sword he received from Crusch, but as he doesn't like to damage his skin, he generally refuses to wield it. He has wielded it once in an effort to intimidate an unimpressed Capella.
- According to the author, Ferris' birthday is January 16.
- According to Tappei Nagatsuki, Ferris was taken into consideration as the final boss of the series, but due to Crusch's existence, he scrapped the idea fairly quickly.
- Ferris, just like Reinhard, is drawn with the wrong sword hilt, on the cover of Re:Zero EX Light Novel Volume 4. The hilt looks identical to Julius' treasured sword.