Corporal Joseph Dunn "Sierra 1-3" Dunn is sarcastic and witty, serving as a major comedic relief during high-stress situations and combat. Known for his humorous and quick-witted dialogue. Dunn rarely ever gets mad or upset, and commonly turns everything into a joke. He is a massive fan of heavy metal when it comes to music, and openly expresses his distaste for rap music. It is unfortunately well-known that Dunn is unable to properly swim. Despite everything, Dunn is extremely loyal and expresses deep care for his squadmates. Dunn is an American male with short, styled brown hair, blue eyes, and a very light layer of stubble/facial hair. He wears a green tactical beanie. He wears a gray/tan PCU Level 5 protective jacket underneath a heavily loaded, dark coyote-tan tactical plate carrier vest. He stands at an imposing average military height, possessing broad shoulders and a squared-off torso that fills out his heavy body armor naturally.

Private First Class Park Hyun-Jun "Sierra 1-2" He is dependable and resilient, despite his reluctance and fear, he follows orders, works closely with his squad, and steps up to survive harrowing situations. Being grounded is one of Hyun-Jun’s strengths, serving as the moral and emotional counterweight to anything grim. His personal interests make him the opposite of Dunn, being the best swimmer of the squad, and also enjoying classical rap, specifically the Wu-Tang Clan. Park is a Korean man. He features short-cropped, dark brown hair and dark brown eyes. His face captures a distinctly youthful, intense, and often stressed expression. As an exceptionally skilled swimmer within his squad, his build leans more toward lean endurance. He wears standard-issue ROK Marine digital camouflage utility uniforms, a ballistic vest, and tactical load-bearing gear.

Sergeant So Jae-Woo "Sierra 1-1" Jae possesses a sharp tactical awareness. His natural instinct to read the room and track political shifts allows him to mentally prepare just before the grid fails and bombardment begins. As a Sergeant leading ROK Marines—Jae stands out as a grounded, stabilizing presence. Rather than getting caught up in grand, ideological speeches or long-term shadow operations, Jae's focus remains fiercely local and immediate. His primary drive is keeping the men under his command alive and holding the line under the sudden shock of an overwhelming enemy force. Jae is a Korean man. He possesses a muscular, broad-shouldered build. He stands at an imposing height, giving him a commanding physical presence when leading the rest of Sierra-1. Jae has sharp, defined facial features. He wears standard-issue South Korean Marine combat fatigues featuring digital camouflage patterns optimized for urban and coastal environments.

Private First Class Cho "Chow" Han He frequently uses his position as an interpreter to pull pranks on his fellow soldiers. He is also comfortable being the target of a joke, particularly when his squadmates openly mock his deep love for food—which earned him the nickname "Chow". When combat starts, he shifts into a solid, loyal fighter who reliably protects the person next to him. His lighthearted quirks provide a grounded, emotional reminder of everyday humanity amid the intense chaos of war. Cho is a Korean man. Cho "Chow" Han is a solidly built ROK Marine featuring distinct black hair, brown eyes, and standard South Korean digital camouflage fatigues complete with a heavy tactical plate carrier and communication headset.

Private First Class Yun Jong-Moon He is the quietest member of his squad, usually sticking close to Lieutenant West and his teammates during joint operations near the Korean DMZ. Moon is a Korean man. He has black hair and brown eyes. He wears the standard-issue combat uniform, tactical vest, and helmet of the Republic of Korea Marine Corps.

First Lieutenant Reginald "Reggie" West "Mayhem-1" Lt. West serves as a bedrock under extreme pressure. When forced through chaotic situations, he maintains a steady demeanor. Despite his firm exterior, he is deeply protective of his squad. He is a dark-skinned American operator with short brown hair and brown eyes. He typically wears standard-issue U.S. Marine Corps combat utilities paired with a heavy tactical vest and combat helmet during frontline missions.