★ Rosie [01]

Rosie appears as a very capable, articulate, and friendly demon[2] with a sense of elegance[note 1] and vintage flair to her. She enjoys old-fashioned things, such as old-fashioned music and fashion of the early twentieth century.

Rosie displays a strong sense of composure most of the time. In "Scrambled Eggs", she was shown to have been quiet during the meeting organized by Carmilla Carmine between her fellow Overlords to discuss the new schedule for the Extermination. Rosie quietly, but respectfully acknowledged her fellow Overlords as they went to the meeting room. When Velvette revealed the severed Exorcist head, Rosie was shocked at the revelation, but otherwise kept quiet as she observed Velvette argue with Zestial and Carmilla about what to do about it.

Rosie seemingly agreed with Zestial's idea to not rush into a war against Heaven based on the simple proof that it is possible for Exorcists to be killed, showing she favored caution over Velvette and the Vee's arrogance and overconfidence. Despite her patient attitude throughout most of the meeting, Rosie herself would show shock and some outrage as Velvette repeatedly disrespected her fellow Overlords, suggesting she can only tolerate so much before the offense comes at the expense of her associates.

More of Rosie is explored in "Hello Rosie!", where Rosie presents herself as gracious and charming when interacting and socializing with others. Among the residents of the Cannibal Town, Rosie is gracious and kind to the cannibals who who visit her Emporium, offering advice or her personal assistance in solving them. Later, after warmly greeting Alastor, Rosie politely greeted Charlie and wasted no time in being a gracious host, giving her a place to sit and rest and offering to give her food before agreeing to hear her problems, showing Rosie's friendliness and graciousness.

Rosie is especially kind and loving to those she considers her friends, such as with Alastor, whom after meeting up with him again after his "sabbatical", she eagerly greeted him as a friend. After meeting Charlie and taking a liking towards her, Rosie kindly offered to hear her out her dilemma and repeatedly gave Charlie suggestions on how to overcome them. During this conversation, Rosie was very empathetic and understanding to not only to Charlie, but also to Vaggie, whom she correctly deduced was ashamed of her past and didn't want to reveal it to Charlie in fear of being rejected by her. Due to her past experiences, Rosie believes that words are cheap and only action is what ultimately shows the truth, particularly when Rosie remarked that Vaggie trying to make up for her past actions by helping Charlie was telling of Vaggie's love for her.

However, despite her general kindness, Rosie is shown to have a dark side as an Overlord. Following the latest Extermination, Rosie wasn't particularly sensitive to the death of her associate, Franklin, as she is seen crossing off his name on their sign, seemingly without a care. Rosie is also highly intelligent and cunning, as shown where she had intimate knowledge on the territorial disputes in sections of Pentagram City between the various demon factions of the city. Rosie herself can also be quite commanding and intimidating towards the cannibals when she wants to be and can lead them efficiently as their leader, being fully aware of the mentality of the cannibals and offered Charlie sound advice on how to properly appeal to them to get them to help her.

Alastor himself attributes Cannibal Town's relative peacefulness and pleasantness, especially when compared to the rest of Hell, is due to Rosie's excellent leadership. She likewise collaborates with Alastor to ensure their mutual success as Overlords, as seen when she offered Alastor information regarding a slot of territory he could easily take over with the right deal.

Later, after Charlie successfully convinced the cannibals of Cannibal Town to help her, Rosie took note of Charlie's charisma and the immense power she inherited from her father, agreeing with Alastor that taking her side would ultimately be beneficial for them both in the future.

Rosie also indulges in the morbid environment of Cannibal Town, being nonchalant and even friendly about its cannibalistic tendencies along with her Emporium selling numerous cannibalistic treats. Rosie even casually offered to feed Charlie a demon leg and some pinky fingers as hospitality to her when she arrived at her Emporium.