Nifa was relatively of slim build and average height girl with short dark hair that had straight bangs and straight ends. She had bright eyes, was only slightly taller than Levi Ackerman and was usually seen wearing the standard Survey Corps uniform with the usual green hood. When dressed casually, she was seen to wear a filled, loose-fitting, long-sleeved dress with dark boots and a front laced corset at one point.
Nifa appeared to be a loyal person as she was allowed to record the details of Erwin Smith's meeting with Dot Pixis, and was then entrusted to pass the information to others. She acted serious most of the time but was still shocked at how Levi treated Historia. However, she was shown drinking what it can be assumed to be an alcoholic beverage before giving the report.
After Hange's squad rescues a group of Survey Corps recruits at Utgard Castle, Nifa is present when they return to Wall Rose. Upon ascending to the top of the Wall, Hange leaves Ymir, who was heavily injured at the castle, in Nifa's care.
After the appearance of the Colossus and Armored Titans, Nifa helps tend to the soldiers on top of the Wall, scalded by the Colossus Titan's steam. She speaks with the worried Connie Springer and Historia Reiss, before leaving the Wall to engage the Armored Titan as part of Hange's squad.
Nifa observes the battle, encouraging Eren in his fight against the Armored Titan, seemingly near defeat. However, the Colossal Titan falls off the Wall, dealing a devastating blow to the soldiers below, and knocking Nifa out.
Nifa is next seen after Eren is rescued, at Squad Levi's new base. She and the other officers of the Fourth Squad sit in a meeting with Levi and his squad, as they discuss the plan for Eren to seal Wall Maria by hardening his Titan body like Annie Leonhart was able to.
Nifa arrives during the meeting of Dot Pixis and Erwin Smith with a note informing Erwin that the Reiss family are the true rulers of the Walls, and Historia is part of that bloodline. She then joins the meeting and begins to take notes on what they both say and on Erwin's orders.
She leaves the meeting and heads to Levi's location, riding through the night to deliver Erwin's instructions about replacing the King with Historia if Rod Reiss does not agree to work with them. She is hesitant to talk about the specifics in front of Dimo Reeves and his son, but Levi insists that they hear it as well. Nifa begins to explain the plan, but is forced to stop when it is revealed that Levi has not yet informed his squad of the Reiss family's position as the true royal family. Once they have been informed, Nifa tells them of Erwin's plan to hand over Eren and Historia to the Interior MPs, in order to follow them to wherever Rod is hiding.
Following the plan's failure, the Interior MPs manage to capture Eren and Historia, killing Reeves in the process. Levi, Nifa, and other members of the Fourth Squad manage to locate the carriage that is being used to transport Eren and Historia to Rod. While they are tailing the MPs, Levi asks Nifa if she is familiar with the mass murderer "Kenny the Ripper", claiming to have been raised by him. Assuming that Levi is joking, Nifa is appalled by the claim and goes back to watching the carriage. As she is watching, she fails to notice that Kenny himself has quietly flanked them, and is shot in the head and killed by him.
- In a Q&A with FRAU Magazine, Isayama stated that Nifa was the most stylish member of the Survey Corps.