Immortalize

The Infinite Eternity, Immortalize (永劫無限(イモータライズ)), is a key term in the course of the series' story.

Information

The true meaning behind the term hasn't been explained. However, Hilda often mentioned it when conversing about the process of becoming a Re-Birth.

Seven Days Immortalize

On very rare occasions, the Hollow Night will continue longer than normally. This period is known as the Seven Days Immortalize (永劫無限の七日間(セブンデイズイモータライス)) and is told to be feared by people.

It is told that Hilda can accomplish her goal during this period. After she is defeated by Hyde, she hints that the next upcoming Hollow Night will be "Seven Days Immortalize".

Sys:Celes

Initially referred to as Sistema Celeste, Sys:Celes is an alternative term for the Immortalize that was used a few times by Kuon. Functionally, Sys:Celes and the Immortalize mean the same thing.

Trivia

• In the very first trailer, the term "Immortalize" was written above "Hollow Night" suggesting they might be synonyms, but after the actual release of the game the terms were separated.