Najenda is a former General of the Empire who defected to the Revolutionary Army and became the leader of the assassin group Night Raid. Her disillusionment with the Empire began during an expedition against the Ban Tribe led alongside Esdeath, where she witnessed horrific atrocities that ultimately drove her to abandon her position and join the rebellion. During her defection, she sustained severe injuries in a confrontation with Esdeath, losing her right arm and one eye, which permanently reduced her physical fighting capacity to roughly forty percent of its original strength. She now uses a mechanical prosthetic arm that she employs effectively in combat.

Najenda possesses a taciturn, sharp-minded, and level-headed personality. She leads Night Raid with a surprisingly gentle but firm demeanor, balancing authority with care for her subordinates. Her boyish appearance has earned her the nickname The Hunk of the Rebellion. She is guided by a strong moral compass and a deep desire for justice, which fuels her disgust toward the Empire's cruelty. Her motivations are rooted in a principled commitment to overthrowing a corrupt regime, and she demonstrates a willingness to make personal sacrifices for the cause she believes in.

Her primary role in the story is that of Night Raid's commander and strategist. She is responsible for mission planning, intelligence coordination, and serving as the main liaison with the Revolutionary Army headquarters. While she often leaves field operations to her subordinates, she remains a capable fighter when needed, compensating for her physical limitations with tactical brilliance and her prosthetic arm. She originally wielded the Teigu Pumpkin but passed it to Mine after her injuries made it impossible for her to use it at full potential.

Najenda's relationships with other characters highlight her leadership abilities. She recruited Akame into Night Raid after a mission to assassinate her, convincing Akame to defect to the rebellion instead. She works closely with every member of the group, including Tatsumi, Leone, Lubbock, and Mine, and her interactions with them showcase her ability to inspire loyalty and trust. Her adversarial relationship with Esdeath is deeply personal, given that Esdeath was the one who inflicted the wounds that permanently weakened her. She also shares a strong bond with Lubbock, who defected alongside her from the Empire.

Throughout the course of the story, Najenda undergoes significant personal development. She evolves from a disillusioned Imperial officer into a dedicated and resilient leader of the Revolutionary Army, growing more determined to see the Empire fall. Her experiences shape her into a figure who is willing to bear heavy personal costs for the sake of justice. After the revolution succeeds, she continues to fight alongside Akame to protect the newly established nation from external threats, and she never marries but instead adopts a child.

Najenda's notable abilities center on her strategic thinking and leadership. She is highly skilled at analyzing situations and issuing precise orders, and her years of military experience make her a natural tactician. Her physical combat skills remain formidable despite her reduced strength, and she has learned to use her mechanical prosthetic arm as a dangerous weapon in close-quarters fighting. She possesses significant influence and political acumen, serving as the main link between Night Raid and the broader Revolutionary Army command structure.