Blood Sea Rubra Abyss

Overview

The Blood Sea (Rubra Abyss) is an abyss filled with crimson liquid that spreads through the deepest parts of the Blood Chapel ruins. Whether its true nature is blood, or something else that merely resembles blood, remains unsolved. It is said that secrets of lost ages lie sunken in its allegedly bottomless depths.

Geographic Features

Location

Located deep underground beneath the Blood Chapel ruins, the space once used as the chapel’s secret sanctuary has, at some unknown time, become filled with blood-colored liquid. It appears on no ordinary maps, and only a very limited few know its location.

To the east lie ruins called the “Crimson Cathedral,” and some theories suggest a connection with the red water that fills its floors. Reports claim the water levels of both change in tandem, though this should be impossible given the distance.

Scale

The exact dimensions remain unknown. According to explorer reports, the sea of blood extends as far as the eye can see, while the ceiling dissolves into darkness above. Regarding depth, many testimonies claim it is “bottomless,” though none have actually reached the bottom.

Environment

It constantly emits a faint phosphorescence, illuminating the surroundings with dim light. The air is thick with the scent of blood, yet strangely lacks any stench of decay. The temperature is close to body heat, and those who touch it describe it as “seeming alive.”

Anomalous Phenomena

Blood Rejection

When ordinary living creatures touch the Blood Sea, they exhibit violent rejection reactions. However, certain mechanical lifeforms, particularly subspecies of the genus Cathedrion, have completely adapted to this environment.

Non-adhesive Properties

Though blood may drip from objects immersed in the Blood Sea, it rarely adheres. The blood is said to refuse even to touch beings imbued with sanctity.

Memory Echoes

Those who linger long in the Blood Sea report glimpsing “someone else’s memories” that are not their own past. Whether these are the final moments of Adelia the Blood Saint, or fragments from an even more ancient era, remains unknown.

Inhabiting Entities

Sisters of the Blood Depths

Cathedrion Noctael subspecies Cruoris. Mechanical nuns who offer eternal prayers within the Blood Sea.
→ See Sisters of the Blood Depths for details

Blood Crystal Insects

Small mechanical lifeforms that rarely crawl out from the Blood Sea. They harbor blood crystals within their bodies and are prized by collectors.

Silent Shadows

Mysterious entities that exist only in witness testimonies. Said to lurk in the depths of the Blood Sea, dragging down those who approach.

Blood Crystals

Red crystals harvested from the bottom of the Blood Sea. They function as powerful catalysts but are said to gradually drain the user’s life force.

Crimson Holy Water

The liquid of the Blood Sea refined through special methods. It serves as an indispensable ingredient in certain rituals.

History and Lore

Origins

The prevailing theory holds that when Adelia the Blood Saint poured her own blood upon the earth as her final miracle, that blood seeped underground to form the Blood Sea. However, ancient documents suggesting its prior existence have also been discovered.

Blood Baptism

The Blood Cult once conducted baptisms in the Blood Sea as the final trial for adherents. Survivors were revered as “those chosen by blood,” though many lost their sanity.

Reason for Sealing

It is said the true reason for abandoning the Blood Chapel was fear of the Blood Sea’s expansion. Reports claim the water level continues to rise gradually even now, though this lacks confirmation.

An old map depicted the Blood Chapel and Crimson Cathedral connected by underground waterways. If true, the two chapels may have originally been one enormous sanctuary.

Warning to Explorers

Approaching the Blood Sea is extremely dangerous. The fate of those who touch the blood without protection is most tragic. Furthermore, prolonged stays risk disturbing mental equilibrium, with the danger of becoming entranced by the Blood Sea and never returning.

“Blood remembers, blood calls. The crimson tide welling up from the depths shall eventually swallow the world. Then, we shall become one within the blood.”
— Final testament of the Blood Cult’s last Archbishop