Sijun, a avid reader and fan of the novel "Eternal Rebirth," sat in his dimly lit room, eyes glued to the final page. He had read the series countless times, but the thrill never faded. As he finished the last sentence, a strange sensation washed over him. The room began to blur, and he felt himself being pulled into the world of his favorite novel.

When his vision cleared, Sijun found himself standing in the midst of a desolate cityscape. Ruined buildings and overturned cars littered the streets. A faint hum filled the air, and the sky was a deep, foreboding crimson. A sleek, futuristic watch materialized on his wrist, displaying a sleek interface:

*System Online*

*Welcome, Spectre (Sijun)*

*Your mission: Guide the Protagonist, Joon Woo (Mammoth), to prevent the destruction of the world.*

A holographic guide appeared before him, projecting an image of Joon Woo's profile:

*Protagonist: Joon Woo (Mammoth)*

_Regressor (87th cycle)_

_Strength: S+_

_Intelligence: S+_

_Agility: S+_

_Humanity: 12%_

The guide's voice echoed in Sijun's mind, "Joon Woo, the Mammoth, has lost his humanity due to repeated regressions. He is now driven solely by his desire for power and survival. Your goal is to gain his trust and help him regain his humanity. The fate of the world rests on your success."

Sijun took a deep breath, determination burning within him. He was ready to embark on this perilous journey.

As he navigated the ruins, Sijun stumbled upon a horde of zombies feasting on a corpse. He instinctively reached for a nearby pipe, and his status window appeared:

*Spectre (Sijun)*

_Level: 1_

_Strength: C+_

_Intelligence: B+_

_Agility: B+_

_Experience: 0/100_

With a deep breath, Sijun charged into battle, pipe in hand. The zombies were no match for his quick wit and agility. As he fought, he noticed a figure watching from the shadows – Joon Woo, the Mammoth.