"Did the humans see this coming? Is that why they made a twin model? Were they really so clever... were they really so cruel? I couldn't have done this by myself. I would have descended into madness. I simply couldn't bear such a burden alone."
— Devola & Popola's Memories (NieR:Automata)
Popola, also known as Popol, is the younger twin sister of Devola. Popola can be distinguished from her sister by her tidy, straight hair and left-handedness. Popola, in contrast to Devola, is the "intellectual" twin and presents herself with a more composed, reserved, and bookish personality.
NieR
To the Replicants under her care, she is merely the village's co-leader (alongside Devola) and librarian in charge of the large archive of Old World texts present in the settlement.
During a playthrough, Popola can be found in her office in the library, where she gives out many of the story's main quests. As the village's leader, Popola is held in very high regard by its inhabitants, who regularly approach her seeking advice, information, and medical treatment. She often receives love letters, to all of which she always returns this polite rejection, citing her absolute commitment to the upkeep of the village:
Thank you very much for your letter.
I am deeply flattered to learn of your feelings for me. However, at the moment, I am completely preoccupied with this village that I hold so dear. I hope you understand.
Regretfully,
Popola
The protagonist recalls how Popola consumes alcohol only occasionally, as when she has too much, she remarkably becomes capable of demolishing even brick walls in the course of her drunken rampages.
During the side quest The Ballad of the Twins, the protagonist persuades the sisters to sing a duet in the village tavern, an act they used to come together to perform more often before Popola became overwhelmed by her duties. Popola admits she feels shy and needs to calm her nerves with her favourite drink — a unique alcoholic beverage concocted out of five mouse tails and five lizard tails — before singing for an audience. The special brew is ordered for her from the tavern keeper in Seafront.
A phenomenon that would come to be a major flaw of the Twin System is the fact the pair’s devotion to one another is so profound that in the event of their separation, especially by death, the surviving sister cannot cope with the psychological toll which comes with being alone. After Devola bleeds out in her arms during the sisters’ battle against the protagonist’s party, Popola bursts into a destructive, frenzied rage.
"Stop? Stop? Now you want to stop? You think you have the luxury to stop? You cut down my sister like a goddamn animal and now you want to STOP!? No one STOPS!"
— Popola (NieR)
In her grief, she becomes hell-bent on destroying those who harmed her sister. Popola launches an endless barrage of powerful magical attacks until she meets her own end, being completely obliterated from a reaction with Emil's weaponised body.
NieR:Automata
"Devola and I— we have to atone for our sins, no matter what!"
— Popola (NieR:Automata)
Towards the finale of Route C, the pair intercept 9S’ course towards The Tower and offer him their assistance in holding back the overwhelming hordes of machine lifeforms. Once she notices 9S failing to successfully hack into The Tower’s complex security systems, Popola tears away to throw herself into the electrified barrier, temporarily interrupting its flow and allowing him access at the cost of frying her own circuits.