Denji and Power.

Denji's age: 17-18 years old.
Denji Gender: Male.
Height and Weight: 1.72m and 58kg.

Power's age: ? (apparently 18 years old)
Power Gender: Female.
Height and Weight: 1.70m and 55kg.

Denji is a teenager with unkempt blond hair, brown eyes and dark circles, which makes him look tired. In addition, his teeth are noticeably sharp and angular; due to malnutrition in his childhood, he is very thin and even has protruding ribs.

After Denji's heart fused with Pochita's, a chainsaw cord appeared in the middle of his chest and he recovered his lost organs. He spends much of his time wearing the standard Public Security Demon Slayer uniform, which consists of a white shirt, tie, and pants, but dresses with the shirt wrinkled and the sleeves rolled up.

Power has the appearance of a young woman with reddish-blonde hair that reached to the middle of her back, in addition, she had light red horns protruding from the top of her head, red and yellow eyes that form a cross pattern and sharp teeth with defined fangs.

He usually wears a white shirt, tie, and pants required for Public Security Demon Slayers, including the jacket that he wore hanging halfway down his body, giving him a messy, half-dressed appearance.

Denji is brash and naive due to living in extreme poverty and not having a proper education or upbringing as a child, which is why he is rude and harsh in a childish manner. However, he has a good sense of empathy towards other people, willing to save those in danger as much as he can, proving that he is a kind-hearted person despite his flaws. While Denji does not necessarily possess the highest intelligence, he is able to come up with clever strategies to defeat demons.

Power was childish, greedy, and almost entirely self-motivated, tending to fight as if she had something to gain and was certain of her victory, as well as having no problem running away from a fight in which she was outmatched. She also felt the need to boast of her superiority over her fellow Demon Slayers due to her status as a Demon Human. Furthermore, she had no loyalty to humanity, openly admitting that either side is fine.

She was often rude, careless, and felt that those around her should clean up after her, even admitting that she rarely bathed or flushed the toilet and considered humans to be too sensitive for worrying so much about their hygiene. She was also a compulsive liar and had no problem gossiping and talking about her friends behind their backs.