Stone of Regression

History

The Stone of Regression appears as the reward for conquering the seventy-seventh floor of the Tower of Nightmares. It initially blocks the entrance to the next floor, and the advance force discovers its item description only after breaking the massive stone apart. Hwang Inchan becomes its first known user; he disappears and cannot report whether the promised regression succeeded, but other Walkers begin taking fragments almost immediately. (Chapter 1)

As Tower Impacts devastate Earth and the climb becomes more lethal, pieces of the stone become objects of trade, fear, and competition. Most surviving Walkers choose regression, while Jaehwan rejects the premise that a past worldline can replace the present they abandon. He forms Carpe Diem from others who initially make the same choice, although companions continue to die or leave until only Jaehwan and Kim Yoonhwan remain. (Chapter 1)

Yoonhwan pretends that an ordinary stone is a regression fragment so Jaehwan will continue climbing instead of staying with him as he dies. Later worlds repeatedly echo the item's form: the Metaverse's dream cocoons resemble Stones of Regression, and memories of the item become part of Jaehwan's uncertainty about whether Chaos and the Abyss are another constructed dream. The final modern-world narrative also returns to debates about regression stories and branching universes. (Chapters 1, 15, 137–143, 237–257)

Properties and use

The System identifies the Stone of Regression as a Legendary item that sends its user to the period shortly after being summoned to the Tower while preserving current memories. It can be divided, allowing many Walkers to carry and activate fragments. The corpus frames the result as a separate timeline or worldline rather than restoration of the abandoned present, although the exact destination shared by different users remains a hypothesis rather than a verified mechanism. (Chapter 1)

Beastrein later reveals internally that the item was not in the Tower's manual and was never an intended part of the cultivation facility. He declines to erase it because manipulating the record could endanger his standing with the contracted harvester. The stone can therefore disrupt a Tower's population while remaining outside even its administrator's planned rules. (Chapter 8)

Associated characters

• Jaehwan: His refusal to use the stone establishes his commitment to the existing world and shapes every later rejection of comforting substitutes.
• Kim Yoonhwan: Yoonhwan uses a false fragment to conceal his fatal condition and send Jaehwan onward.
• Sakamoto: Sakamoto proposes the branching-world interpretation that Jaehwan remembers in the modern world.
• Beastrein: Beastrein recognizes the stone as an unplanned intrusion into the Tower.