Crusch Karsten (クルシュ・カルステン) is the Matriarch of House Karsten and a candidate to become the 42nd King of Lugnica.
Crusch is a beautiful woman with amber eyes and long dark green hair that reaches the middle of her back. Even though she is a woman, she generally tends to dress as a man and is described to be someone whose impression changes if she wears a dress and smiles.
While normally calm and serious, Crusch is honest, sincere, right, being the type of person who is destined to stand above others, though she has talent and has worked hard to reach where she is now. She is already the head of her family, finishing her work better than her father. She prefers to act herself and has the pride of a warrior. Crusch is also gentle, often believing the false knowledge jokingly told to her by Ferris, and sometimes displays an airheaded side. Like her mother Helena Karsten, she is shown to be ruthless and reckless.
Crusch is also dense toward any feelings of love above kindness, often not understanding why certain people behave a certain way, such as when she sometimes didn't understand Fourier's behavior. However, this only applies to feelings of love directed towards herself, as she has been shown to comment on the feelings of others.
Currently, her memories were eaten by Ley Batenkaitos when she, Rem, Hetaro Pearlbaton, and the rest of the subjugation army who fought the White Whale were returning to Lugunica when she encountered Ley and Regulus in Arc 3.
Crusch was born as the only daughter and heir to the Karsten family, one of the most powerful noble families in Lugnica. Even as a child she was considered an oddity among the nobility for being more mature than other children her age. Moreso as a girl who favored things like weapons over finery. As she grew older Crusch would develop a preference for men's clothing, and take on more masculine pursuits like learning swordplay which earned rumors about her from other nobles. Crusch held a strong fascination with the history of Lion Kings (獅子王 Shishiō) which would come to serve as the basis for her radical but conflicted ideas about Lugunica present state. Her close friendships with both Fourier and Ferris would further have a huge influence on these aspects of herself and facilitate finding the balance between Crusch as a woman and Crusch the as noble she felt needed to become lead House Karsten.
On Crusch's 17th birthday an incident with Great Rabbit occurred in the Karsten lands. Her efforts and leadership there would latter play a crucial role in her father passing down the position as the head of the family to her couple weeks afterward. Several years later, Crusch would catch wind of trouble afoot at the House Argyle, through a report by her advisers. Not wanting this to burden Ferris whom still had trauma from his time with the Argyles nor let what was happening to affect her attendant's standing among the knights in a very delicate period that would decide his future, Crusch would endeavor to take off the problem quietly herself and confer with Fourier to keep Ferris away from it.
Crusch would directly head to Argyle estate to confront Biehn Argyle and Miles to learn the truth of the matter. After a tense conversation Crusch would fall into a trap she is drugged by the scent of odorless poison in the tea she had been given. She would find herself held in the same underground cell Ferris had lived in for years before his rescue by her. After a conversation with Biehn, Hannah Regret would later appear to loosen her manacles so she could escape when it was time. Crusch still completely unsure which side she was on would inquire about her motives and why she was betraying him. Hannah would only mention that it was out of love and Crusch wouldn't understand. It was at this point Crusch noticed the similarities between Hannah's appearance and Ferris, but the maid would leave before she could ask. Miles would soon visit Crusch himself intending to break her will in preparation to make off with her and Ferris later, only for Crusch to reverse the situation to his shock by cutting him and the corpse soldiers around down. She then met up with Julius in the manor's first floor and then a distraught and shaken Ferris. The three would escape the blazing inferno the place had become.
A year later, due to her increasing amount of workload brought about by the royal family being unable to fulfill their duties, Crusch found little time to visit Fourier after he fell ill to the unknown epidemic sweeping through the palace. Eventually, one day during one her rare visits she brought Fourier out to gardens in the palace courtyard unbeknownst to her his would be the last time the two would speak. Reminiscing about the old days and reaffirming their childhood promise Fourier would die suddenly, but peacefully. During the day the same day the current king would be the last royal to succumbed ending the Lugnica line. In the emergency meeting hereafter, an emotional Crusch privately became outraged by how cavalier the royal court had treated this national tragedy moving on quickly as were a footnote compared to the loss of the contract between the kingdom and dragon. It was there then that the Dragon Insignia, as well as prophecy regarding the next step the country should take, would be revealed. Crusch is discovered as the first of the five potential candidates deeded worthy to lead the country. Learning this with strong conviction, Crusch would return to the garden where Fourier died with Ferris and vow to forever sever the tie between the dragon and Lugnica whose influence she became convinced had distorted the way Lugnica should be.
Divine Protection (加護 Kago): Crusch has the Divine Protection of Wind Indication (風見の加護 Kazemi no Kago). It enables her to read the wind and to see invisible things just like the wind. Crusch can also use it to read the situation of others' emotions, making her able to tell if someone has lied.
Wind Magic: Crusch is highly skilled at Wind Magic, allowing her to combine it with her sword skills for devastating results.
- One Blow, A Hundred Felled (百人一太刀 Hyakunin Hitotachi): Crusch combines her sword skills and Wind Magic to unleash a sword strike that enables her to cut anything within her range of vision with an invisible blade.
Skilled Swordsman: Crusch is considerably skilled at using a sword in combat, or using her Wind Magic to act as one.
Equipment: She wields the Lion Rampant, a sword which bears the lion-shaped crest of the Karsten family on its cross-guard.
- According to the author, Crusch's birthday is April 4.
- She has a fear of heights, also known as Acrophobia, as this was mentioned in Arc 5.
- She is remarkably sheltered when it comes to romance, at least when it is directed at her.
- She has a habit of raising her finger upward when she is going to explain something.
- On her 14th birthday, her father had gifted her a dagger that bore the head of a lion on its pommel which became her favorite keepsake as remind her of the Lion Kings of Yore.