In the past, Clind trained Frederica to help her control her beast form. Following the events of Arc 4, he was brought into the Emilia Camp by Roswaal to oversee Subaru's training after the boy officially became Emilia's knight.
Despite being at least 400 years in age, Clind appears to be a handsome young man with a slender face with a tall, lean body. Along with that, he has eyebrow length blue hair. Clind wears a well-starched black butler uniform with a frilly blue tie and sports a monocle on his left eye.
Clind is well-mannered, highly considerate of others, is extremely skilled as a servant, and tends to add idioms to the end of his sentences. Despite his good traits, he sometimes jokes around a little while behaving in a polite manner and is also a lolicon. However, he claims that he isn't drawn to them because they're young but rather because they have pure and genuine souls and people who have such souls are typically young in age. Because of this, he was able to determine that Emilia was mentally young for her age and that Ryuzu's soul was much more mature than her appearance suggested. Although he has known Frederica for ten years starting from the time he began working as a manservant, he tends to be prejudiced toward her appearance, resulting in bad relations between the two of them.
Being born before the Great Calamity, Clind was acquainted with the Witches and Warlocks of that era. At some point in time, he made a contract with a young Roswaal A Mathers which entailed Clind to protect Roswaal's property by any and all means. According to Roswaal, he had compensated the contract with Clind by forming a united front and defeating Roswaal's yet-unnamed nemesis. Clind has faithfully abided to his contract ever since, due to his ability to perceive souls and sensing Roswaal A Mathers' soul in the bodies of his descendants.
At some point in the future, Clind came in contact with an unspecified Witch Factor, which granted him an Authority he possesses to this day.
Following the end of the Demi-Human War, Clind accompanied Roswaal J Mathers (Julia Mathers) to a pub where she met with the Sword Demon, Wilhelm van Astrea, where they discussed the threat of Stride Vollachia. During their talk, however, the trio were assaulted by a group of Shinobi, who were swiftly dispatched by Roswaal, Wilhelm, and Clind. Wilhelm noted that Clind's technique was neither sword skill nor magic, but something completely different.
Following Roswaal's death at the hands of Stride Vollachia and his Shinobi, Clind took care of her son, Roswaal K Mathers (Karl Mathers), who inherited the soul of the original Roswaal A Mathers. The duo's only appearance can be traced back to the end of Sword Demon Battle Ballad side story, as Wilhelm met them on Roswaal J Mathers' funeral. During their short exchange, Wilhelm swore he would do everything in his power to help Karl if in need in order to honour Julia who greatly helped him during and after the Civil War. A few minutes later, Karl and Clind left the cemetery.
Sometime in the following decades, Clind was entrusted with protecting and training Frederica Baumann. During that period, he was also transferred to Miload Manor, where he actively continues to work as Annerose Miload's butler.
Authority (権能 Ken'nō): Clind possesses an unknown Authority that allows him to cause damage to distant objects. Though the full extent to how he can use it is not known, in one instance, he was shown to use his Authority in order to crush a person's limbs. He used this technique of assault against the blood specialist Leonardo through the action of spreading his hand, clenching it, and using the word "melancholy" before the action was completed - distinct actions that Hector, the Warlock of Melancholy, had done during his fight with Roswaal A Mathers 4 centuries prior.
Soul Perception: Clind has the power to perceive qualities from the souls of other people. For example, he used this ability to perceive the soul of the original Roswaal within his descendants. Presumably, he is also able to use this ability in order to perceive the "purity" of a person's soul.
Skilled Swordsman: Clind is talented enough with the sword that he can fight with it in emergencies, though he's almost never seen holding a sword or engaging in a sword fight.
Parkour: Clind is skilled enough at parkour to teach it to Subaru. Subaru mentions that he is able to finish the Athletic Zone Garfiel made without rumpling his clothes and without breaking a sweat, calling him inhuman.
Survival skills: He is mentioned by Subaru as being skilled at survival, enough to be able to teach him the basics (finding water, how to start a fire, ect).
Whip: Like his parkour, Clind is skilled at using a whip and taught Subaru the basics on how to use one.
- According to the author, Clind is fond of both boys and girls, as his view on love is rather unique.
- In a Q&A, it was stated by the author that Clind would be an important character in the latter half of the series.
- Clind hinted that he may have accompanied Roswaal J Mathers on her campaigns during the Demi-Human War using some sort of cloaking ability which made it so that no one could detect him, though he wrote his statement off as a joke upon being questioned by Wilhelm.
- Aside from the Witch of Envy, Clind is the only confirmed holder of a Witch Factor who isn't named after a celestial body.
- "so even when beast-changed, she retains her reasoning. Clind prepared her." Garfiel Birthday Q&A
- "To be enraptured by pure, immaculate souls is natural. And it happens that many possessors of such souls are young." One Day II Chapter 2. Section 1.
- Golden Siblings
- "Subaru had Clind watch him practise his parkour, the then Clind defeated Garfiel's obstacle course without breaking a sweat and without ruffling his clothes. He's inhuman." Arc 5: Chapter 3. Section 1.
- "Edible grass and fruits are.... ahh, I was right to learn it from Clind-san. Gotta thank my mentor..." Arc 7: Chapter 1. Section 3.
- "Whips had a longer range and were more difficult to manipulate than movies had made them seem, but in the past year, under Clind's tutelage, Subaru's skill had vastly improved." Arc 5: Chapter 20. Section 1.
- "Clind-san can go for boys, too." askFM Q&A
- "That person is an important character in the second half, so there are various things." Q&A
- "Quite so. Gratitude. But in fact, I was at Madam’s side as well during the Civil War. I turned myself invisible so that people wouldn’t see me. Concealment." Sword Demon Battle Ballad Act 1; Part 4