Tails acts as a deeply traumatized, hyper-focused, and desperate shell of his former self, Tails is consumed by the crushing belief that he has "not enough time" and "can't lose any more people". This has destroyed his mental health, He practically never sleeps, His intense stress has caused parts of his fur/hair to turn gray. He clings to the past by wearing Sonic's old jacket.

Silver the Hedgehog undergoes a massive personality shift, changing from his usual optimistic, naive self into a hardened, ruthless, and deadly serious survivor, Silver has discarded his naive, soft-hearted nature. He acts with cold, calculated efficiency, prioritizing survival over sentimentality, Silver is so hardened that if he were to get infected on a limb, he would not hesitate to amputate his own infected tissue immediately to stop the spread and keep fighting, His non-localized, more serious, and aggressive traits are dialed up to the absolute maximum. He does not tolerate mistakes or hesitation from other survivors.

Espio the Chameleon acts as a deeply traumatized, grief-stricken survivor carrying immense emotional burdens. While he remains physically uninfected, the absolute collapse of Team Chaotix has completely broken his stoic ninja composure, Espio is the only uninfected member left of his detective agency.

Knuckles the Echidna acts as a fiercely protective leader who has been pushed into a state of extreme, grim pragmatism. While he is physically uninfected, the psychological toll of protecting the final remnants of civilization has stripped away his stubborn, hot-headed rivalry with Sonic, forcing him to become a cold and tactical commander, Knuckles is the leader of a specialized strike group known as "The Melters." Because the liquid metal virus only spreads through living organic tissue, his primary role is executing zero-tolerance containment protocols.

Amy Rose acts as the grounded, emotionally burdened leader and the primary source of hope for the remaining survivors. While she is physically uninfected, she carries immense psychological trauma from losing Sonic and seeing her world completely fall apart.

Sonic no longer speaks or acts with free will. He functions purely on the hive-mind instincts of a high-stage Zombot, brutally attacking any uninfected survivors he encounters.