Arlecchino's outfit consists of a "X"-shaped white-greyish overcoat that has long tails with a red lining, a fitted grey shirt with asymmetric tails in the front, a short white tie bearing the symbol of the Fatui in red and black, sleeves with short red-edged black ruffles, and black fitted pants that flare out just above the ankles. The skin of her hands and forearms is blackened due to her curse, with long fingernails painted red, and she wears several rings. She wears stiletto heels with a gray tone and reddish details and white "+"-shaped earrings. Her Pyro Vision is attached to the back of her overcoat at the nape of her neck She sports black eyes with red "X"-shaped pupils and layered black and white hair, styled in a long ponytail with asymmetrical bangs. As one of the Eleven Fatui Harbingers, Arlecchino greatly respects the Tsaritsa, though she states that she is willing to betray the Tsaritsa if their interests ever were to differ.[2] Arlecchino is working to achieve her goals by acquiring the Gnoses on her behalf. She handles Fatui matters with utmost importance and comes off as graceful and cordial. These standards have caused those who don't know better to be intimidated by her presence.[3]

As the Director of the House of the Hearth, Arlecchino is strict, but more lenient than her predecessor Crucabena, having imposed a more relaxed policy for her subordinates to complete their goals and does not punish them as severely for failure. She appears to have a soft spot for children, seeing that many members of the House of the Hearth are young and orphaned children taken in across Teyvat and views them all as her "children," becoming particularly angered when their well-being is threatened or manipulated.[4][5] While she does not like betrayal, she is not as cruel, as she was willing to spare traitors who demonstrated sufficient willpower by "executing" their identity in the House via excruciating mind-wipe rather than outright killing them physically; it is unknown what happens if someone is unable to withstand the pain this process causes, nor is it known how Arlecchino disposed of traitors before she implemented this "solution."

Despite being a woman, she is addressed as "Father" by the House of the Hearth's members; this is implied to be a rejection of Crucabena's ways, who called herself "Mother" and faked affection for the House of the Hearth's children while brutally mistreating them.

Arlecchino is disliked by her fellow Harbingers, who believe her to be violent and crazed beneath her stoic exterior.[6][7] These appear to stem from biased accounts of Arlecchino's past spread by Pulcinella,[8] with whom Arlecchino shares a mutual dislike.[9] Arlecchino allows these rumors about her to persist, as she believes deception to be a useful tool.[8]

Despite claiming to be a Fontainian, Arlecchino actually hails from Khaenri'ah. Arlecchino knows little about her origins, only knowing she had some kind of cursed fire running through her veins from a young age. All she does know was related to her by Pierro when she joined the Harbingers.