Like all Crimson Demons, Arue has dark brown hair and red pupils. Her hair is shoulder-length & end as drills. She also wears an eyepatch identical to Megumin's. She is also consistently described as voluptuous.
Arue initially is described as quiet and composed and is quickly revealed to be clever, albeit mischevious. She has a penchant for storytelling, able to tell the most nonsensical statements with a completely straight face and to make her stories and Crimson Demon culture semi-believable or reasonable to an outsider.
In terms of raw magic power, Arue is the third highest scoring student in her class, only trailing behind the first and second place Megumin and Yunyun respectively. However, for quizzes on Crimson Demon culture that required chuunibyou answers, she always exceeds the teachers' expectations and often get score marks of 100.