Due to publisher feedback, two versions of the protagonists exist; a brother looking after his sister originally exclusive to Japan, and a father caring for his daughter designed for the West.

For the remaster, Kenichirou Matsuda provided a Japanese dub for the adult version, while the brother protagonist's English actors were Zach Aguilar and Ray Chase.

Though critical response to the elder protagonist was generally positive for his caring personality that contrast with his barbarian appearance and relationship with his daughter, the decision to alter the design was the subject of discussion by several writers due to the need to appeal to Western audiences.

The protagonist is joined by Grimoire Weiss, a talking book with access to magic; Kainé, a foul-mouthed swordswoman part-possessed by the Gestalt Tyrann; and Emil, who self-isolates due to his petrification powers.

Retrieving the key fragments, all held by powerful Shades, the protagonist enters the Shadowlord's castle and is forced to fight Devola and Popola, two androids who ran his village and oversee the Replicant system.

[1] Further details around the protagonist are included in Grimoire Nier, a guidebook featuring plot and character summaries, short stories, concept art and developer commentary.

[2][3] The short story Red and Black details the brother protagonist's early struggles caring for Yonah, including prostituting himself to another man before killing him on a Shade hunt and becoming his village's courier with Devola and Popola's encouragement.

There was some pressure to drop the younger protagonist altogether due to budgetary reasons, but Yoko pushed for his inclusion, and as a compromise two versions of the game were created.

[17][21] Yoko, and scenario writers Sawako Natori and Hana Kikuchi all agreed on the backstory element of the protagonist sleeping with women and men for money, though this could not be included in-game.

The final scene involves the protagonist enjoying his happy life with Yonah as requested by Saito, a decision Yoko accepted despite it clashing with his previous work.

[23] The Grimoire Nier scenario was included in the remaster due to the game's larger budget, and a request from producer Yosuke Saito for more fan service.

[31] Yusa found playing the older brother interesting due to his subdued behavior and attitude compared to Okamoto's performance which had a brighter and more hopeful tone.

[5] Okamoto and Yusa returned for the 2021 remaster,[25] and at Yoko's insistence two voice actors were also used for the English release to create dissonance in players with the in-game timeskip.

Aguilar felt honored to be joining the cast as he had looked up to the other pre-established actors in his youth, while Chase enjoyed playing the older version due to both his serious side and displays of "sardonic" humor.

[25] Price was sad that his version of character went unused, but understood the situation upon researching the original game's development and was glad some of his work remained in-game.

[34] RPGFan agreed, saying the game "made me feel like a father" due to how the main character is obsessed with taking care of Yonah, but felt some of his tactics will question the player.

[37] Several writers said that the elder protagonists was one of the earliest examples appealing fathers in gaming, noting it appears to have led to next similar characters like Kratos from God of War or Joel Miller from The Last of Us.

He felt it was common for Western players to have characters similar to the father as protagonist in action games, comparing him to each other and finding the result chaotic.

[42] In general, Z. Zhou from University of British Columbia sees the protagonist to go through deconstruction of the typical hero's journey found in Japanese video games with a fantasy setting.

[39] Kotaku had found him boring, the writer still felt he was too cliche in role-playing games to the point he often wanted Kaine to replace him as the main character.

[49] RPGFan and Electronic Gaming Monthly said found that the brother makes a better relationship with Yonah than the original father due to how his characterization noticeably changes in the time-skip.

[50][51] Aguilar and Chase's performances were also praised by Anime News Network they "split the billing as Nier at different points in his life, and they capture the character's many nuanced shades of anger, resilience, compassion, and undying loyalty.