Ram has medium-length light pink hair that covers her left eye, large darkish red eyes, and youthful features. She wears hair clips and a flower-shaped ribbon on the right side of her hair, along with a maid hairband. She looks nearly identical to her sister Rem, differing only in hair, eye, and ribbon color. Ram usually wears a maid uniform and has a smaller chest compared to her sister, with slightly slanted eyes. At times, she dons a white hooded robe when traveling alone.

In Arc 6, Ram wears a long-sleeved aqua-green dress with white frills at the hem of the skirt, paired with aqua-green boots, black leggings, and an aqua-green cloak with a white design on the hood to protect her from the sands of the Augria Sand Dunes.

Ram appears self-centered, sardonic, and prefers to do things at her own pace. In truth, however, she keeps her distance from others to better understand them. Compared to her quieter sister Rem, Ram is more outgoing and often takes the lead in their relationship. Her sharp and teasing remarks are her way of expressing affection. Although she seems cold and snarky on the surface, she genuinely cares for those around her and is surprisingly kind and forgiving when it matters most.

Despite her seemingly lazy attitude toward her work as a maid, Ram’s lack of effort is due to the constant pain she experiences from the loss of her horn. Her physical limitations prevent her from performing strenuous tasks, but she still fulfills what duties she can, such as managing the Mathers Domain’s paperwork in Roswaal’s absence, something she keeps secret from her sister. In her youth, Ram often struggled with violent impulses driven by her Oni nature, which she managed to suppress until the loss of her horn. Though the injury greatly weakened her, she came to view it as a blessing, believing it spared her from succumbing to her darker instincts.

Ram has always been extremely protective of her sister Rem, recognizing her sibling’s insecurities and doing her best to include her in everything. Even during the destruction of their village, Ram’s only concern was saving Rem, which ultimately led to her servitude under Roswaal. While she initially despised him for his role in their clan’s downfall, her feelings grew complicated over time, shifting from hatred to devotion, and eventually love. Beneath her calm and sarcastic demeanor, Ram deeply worries for those she cares about, though she hides her concern behind cold words and actions. In moments of crisis, her composure can crack, revealing her intense emotions, especially when it involves the people closest to her such as her sister or Subaru.

Ram was born into the Oni Bloodline, where she was once hailed as a prodigy and even called the second coming of the Oni God due to her exceptional talent despite only possessing a single horn. However, after the Witch Cult’s attack on her village, her horn was severed, cutting off most of her power but freeing her from the violent impulses that came with her Oni heritage. Even without her horn, Ram can still enter her Oni Form, granting her immense strength and speed at the cost of severe physical strain such as vomiting blood and being left immobile afterward. Her power is described in terms of shackles, each representing a portion of her Oni strength, and she can temporarily increase her power through connections like Cor Leonis with Subaru or through her bond with Rem’s horn. Since losing her horn, Ram must regularly receive mana from others to survive, relying on individuals with precise mana control such as Roswaal or Julius.

Aside from her Oni heritage, Ram possesses several powerful abilities and skills. Her Clairvoyance allows her to synchronize her vision with others, though using it strains her body and causes physical pain. She shares Synesthesia with Rem, letting them communicate and share emotions telepathically. Ram is also a master of Wind Magic, capable of unleashing devastating attacks such as Al Fura, which can obliterate everything in its path, and creating illusions by combining her wind techniques with hallucinatory scents. In combat, Ram enhances her martial arts with Wind Magic, allowing her to move swiftly and strike with incredible precision and power, enough to battle transformed opponents like Garfiel and Lye Batenkaitos. Beyond her combat skills, Ram is highly intelligent, observant, and educated, excelling in analysis and deduction. She often wields a wand crafted by Roswaal from her broken horn, which helps her channel mana efficiently while minimizing strain, making her a formidable and versatile fighter despite her physical limitations.

As the gifted elder twin, Ram was born with an exceptional talent for mana manipulation and a powerful body that made her the pride of the Oni village. The chieftain regarded her as the second coming of the Oni God, and she excelled in everything she attempted, from combat to cooking. Her natural genius and strength earned her the admiration of everyone around her, including her younger sister, Rem. Despite the praise and attention, Ram remained humble and caring, never allowing her superiority to overshadow her bond with Rem. On the tragic night when the Witch Cult attacked their village, Ram fought valiantly to protect her people and her sister. Though she managed to hold off the enemy for a time, she was ultimately overpowered and lost her horn while shielding a terrified Rem from harm. The sisters would have perished if not for the timely intervention of the powerful mage Roswaal L. Mathers, who saved their lives and took them under his protection.

In the years that followed, Ram and Rem devoted their lives to serving Roswaal out of gratitude and loyalty. Roswaal became Ram’s lifeline, ensuring she received the mana infusions necessary for her survival after the loss of her horn. During her time at Roswaal Manor, Ram learned part of the truth behind the Witch Cult’s attack and discovered the identity of the one who severed her horn, a cultist named Faust. With Roswaal’s assistance, she exacted her revenge. Ram also became the only person aware of Roswaal’s gospel and entered into a contract with him, declaring that his life would belong to her should the future ever deviate from its written path. Though she once vowed to kill him for his role in the tragedy, her feelings gradually shifted from hatred to a complex devotion, binding her to Roswaal through both love and vengeance.