The War Below the Waves
After the chaining of Old Mother — the mighty Kraken that the Sirens had begun to treat with a devotion that bordered on worship — and bounding the Siren King's soul into a chest, the Ancients found themselves embroiled in the war of the Merfolk against the Sirens.
To expand her army on land, the Siren Queen bounded the souls of the Ancients she caught into Mermaid Statues. With the power of the Mermaid Gems, she turned them into what she called Ocean Crawlers and corrupting the gems — now know as Siren Gems. Nowhere was safe, on land or sea.
A Warrior vowing to end the war once and for all, took up her blade and strode fearlessly into the sea, forcing the Sirens to retreat into the darkness. The Ancients used Mermaid Gems to hold an immense power that forced the Sirens to slumber.
Once the Warrior returned home, she brought back with her the curse of a sunken sorrow. The Ancients entombed her remains into the vault of the Shrine of Ancient Tears and sealed it for the danger it contains.
Source
Shrine of Ancient Tears, Journal: War Below the Waves