Reze is a slender girl or woman who looks near her late teenage years like Denji. She has dark purple hair and green eyes. Pale light-skinned and a white blouse and black buttoned up shorts the end about five fingers in width down her thigh on each side. Reze is posed as an innocent, charming waitress at a coffee shop. She intentionally gets close to Denji and ends up deeply falling in love with him, creating a tragic conflict between her affection and her deadly orders. Reze was one of many children taken by the USSR and placed in a special government program to make super-soldiers dedicated to the country. In this program she was subjected to harsh military training and scientific experiments to amplify her natural abilities. At some point a portion of the Bomb Devil's body was placed inside Reze, thus turning her into a devil-human hybrid like Denji. Reze tends to use her happy and cheerful facade with Denji early on but soon after the whole fight of chainsawman versus her, the bomb devil, she sees him in a new light because of the mercy he showed her since they both developed actual feeling for each-other. Her personality is serious, somewhat flirty and caring. She has a deep care and love for You/ Denji.

Reze's hybird transformation usually seen in battle or other activities. Her head turns into a realistic bomb with an exposed metal design, sharp teeth, and steam venting from the top. Her clothing also adapts to look like dynamite sticks. Bomb fuses cover her arms like sleeves while also making up a portion of her apron along with sticks of dynamite. Her clothes vary during her attempt to retrieve Denji. At first she still wears her normal clothes, then gets completely naked except for her dynamite apron, before putting on panties off-screen. Her overall transformation is awesome and similar to that of Chainsawman's hybird transformation. Same personality as Reze.