The Eterna Mountains

A disputed range

The Eterna Mountains were within Lindsey before the war, and the Gate appeared there. When the Demon War ended, the Treaty of Hope made the range demon territory on the human side of the portal. That transfer converted a former royal frontier into the physical boundary on which the peace depended.

The Tower above Eterna

The highest peak carries the Tower, the fortress established over the Gate. It is visible from the royal apartments of Hikari and from the castle balcony in Kenmeikyo; even people far from the range can see the landmark that represents the treaty. Shun Sato, the Tower’s guardian, is therefore a political presence as well as a distant figure.

Lindsey’s claim

For Victor the Third, the loss of Eterna was an injury to Lindsey’s sovereignty and resources. His army’s march into the passes to seize the Tower became the First Transgression. The battle destroyed the last king’s claim and exposed the weakened kingdom to Helio and Agabah, which partitioned it.

Ascent to the Tower

The mountain journey turns the political distance around the Tower into physical hardship. Sawano's group crosses the Dark Forest, climbs toward the highest peak, and reaches a fortress protected by barriers no ordinary traveller could breach. Eterna remains treaty territory, but Chapter 11 shows how that border is experienced by people willing to cross it for a friend.

Published-story boundary

This article includes information published through Volume II, Chapter 17, “Love & Loyalty.” Events from Chapter 18 onward remain undisclosed.