White Whistle

''This article is about the object. For the delver rank, see White Whistle (rank).''

White Whistles are Second Grade Artifacts that can only be used by their original owner. They are made from ”Your Worth”, the Life Reverberating Stones, and given further shape by the user's own modifications to the stone, making each and every White Whistle unique. White Whistles are able to activate dormant Relics.

The White Whistle is a signature characteristic for the few Delvers that are allowed to delve past the 5th layer of the Abyss. Currently there are only a handful of recognized White Whistle users, although it is unknown whether or not all of them are still alive.

Life Reverberating Stone
It is revealed by Bondrewd that White Whistles are made out of Second Grade Artifacts, called Life Reverberating Stones. The raw material required to create a Life Reverberating Stone is a human being. If the person has a firm resolve to sacrifice everything for the whistle's intended user, they can potentially turn into a Life Reverberating Stone. Each Life Reverberating Stone possesses a life pattern unique to the person sacrificed for the stone; the pattern is only compatible with the individual the Life Reverberating Stone is intended for. Hence, the White Whistle can only be used by them.

Some form of consciousness of the sacrificed person remains within the Life Reverberating Stone; as seen when Riko, Nanachi, and Reg found Riko's stolen White Whistle being altered by a Narehate, but Riko stopped Reg from taking it back, sensing that Prushka "did not hate it". Prushka was also seemingly still able to communicate with Riko in subtle signals, as seen during the Fuzosheppu crisis. Futhermore, Faputa was also able to communicate with Prushka to an extent.

Life Reverberating Stones have the strength to pull out the true purposes hidden within certain Artifacts, as seen with the elevator leading into the 6th layer.

In the finalised form of a whistle, Life Reverberating Stones are seemingly able to heighten the output of artifacts or beings like Reg. However, doing so will put a strain on the user, which grows more intense and damaging to their health with short intervals between usage, ranging from exhaustion to passing out with excretion.

Thus far, the only individuals known to have Life Reverberating Stones created from them are:
 * Doni, whose stone was used for Lyza's White Whistle.
 * Bondrewd, whose stone was used for his own White Whistle.
 * Prushka, whose stone was used for Riko's White Whistle.

White Whistle Owners
There are only a few known people who own or have owned White Whistles:
 * "The Lord of Annihilation", Lyza the Annihilator
 * "The Immovable Sovereign", Ozen the Immovable
 * "The Lord of Dawn", Bondrewd the Novel
 * "The Lord of Mystery", Srajo the Obscure
 * "The Lord of Guidance", Wakuna the Chosen
 * Riko

Trivia

 * Currently, Riko is the only person known to be in possession of more than one White Whistle; her mother's was passed down to her after it was brought up to the surface by Hablog, and Riko's own White Whistle which she obtained at the end of the Lord of Dawn Arc following Prushka's demise and subsequent transformation into a Life Reverberation Stone.
 * A White Whistle recovered after its owner's death or Last Dive is traditionally given to their surviving family or descendants. If it is declined or the Delver has no living relatives, the whistle becomes property of the Delver's Guild and is kept at their headquarters in Orth.