The Sanctuary first comes into prominence towards the end of Re:Zero season 1. When Irlam village is on the verge of being attacked by Petelguese Romanee-Conti and his fingers, some of the inhabitants from the village are moved temporarily to the Sanctuary.
The Sanctuary was at that time revealed to be a place under the protection of the Roswaal family for generations making it a safe option to shelter the residents of Irlam.
However, in Re:Zero Season 2 we realize that the Sanctuary is not exactly a “sanctuary”. Subaru and Emilia visit the Sanctuary to bring back the residents of Irlam who were being sheltered there and Roswaal Mathers. To their surprise, they find that the Sanctuary is a small village located in the forest of Kremaldy.
Contrary to the name, the village is poor and consisted a bunch of buildings which were almost in a state of ruin. They realise that all inhabitants of the Sanctuary were demi-humans.
More flags are raised when the Sanctuary is termed as the “Witch’s Graveyard” and the residents are said to be trapped inside. The sanctuary had a barrier which prevented the demi-humans from leaving the sanctuary and Roswaal requests Emilia’s help to liberate the people stuck in the sanctuary.
So what exactly is the Sanctuary and why are the demi-humans stuck there?
In short, the Sanctuary is a village which was created by the Witch of Greed Echidna 400 years ago. It is currently her resting place and is under the supervision of the Roswaal family.
The following part of the post contains MAJOR SPOILERS for Arc-4 of Re:Zero web novels. Read ahead at your own discretion!
What exactly is the Sanctuary?
The Sanctuary was founded 400 years ago, at a time when the witches still roamed free in the world of Re:Zero. The Witch of Greed Echidna is the founder of the Sanctuary and it is currently her resting place.
On the outside, the Sanctuary was established so that demi-humans (or humans with mixed blood) could live without fear of the outside world. In the past, the demi-humans were a race that were treated unfairly and victimized.
Echidna assured them that they would be safe inside the Sanctuary and then used their mana in order to create a barrier that would protect the place.
But in reality, the Sanctuary was built for Echidna’s personal reasons.
In the past Echidna supposedly had a huge rivalry with Hector, who was known as the Warlock or Demon of Melancholy. While not much has been revealed about Hector in Re:Zero, it is implied that he was stronger than Echidna and that she was being pursued by him.
Echidna is a witch known for her vast knowledge and not her fighting prowess. And hence she had to come up with a cunning solution in order to stop Hector.
The role of Demi Humans in Sanctuary:
Under the guise of protecting the demi humans, Echidna lured them into the sanctuary and in a way trapped them there. Their mana was extracted, and it would then be used to form a barrier, whose original purpose was to shield Echidna from Hector.
The demi humans, thinking that the Sanctuary was the only place they could exist peacefully, decided to give their mana, without knowing the true purpose behind it. So in a way, Echidna exploited the situation to her best use. The demi humans would get a place to stay safe, and Echidna could be in peace without feeling threatened by Hector.
However, the extracted mana alone was not enough to complete Echidna’s dream. For the barrier to activate, it needed a focal point or a nexus that would hold it in place. But before the preparations for creating a nexus could be complete, Hector confronts Echidna.
Ryuzu Meyer and the Barrier:
Echidna makes haste in the preparations for completing the barrier. For this purpose, she chose the help of Ryuzu Meyer, who was an inhabitant of the Sanctuary at that time. In order to help this happen, Roswaal offered to stall Hector and buy Echidna some time.
But in the process, Roswaal was gravely injured. Somehow, he survived the battle, but ended up inheriting some traits of Hector, which is very suspicious!
Ryuzu Meyer willingly turned herself into a crystal in order to help Echidna and form the barrier around the Sanctuary. This barrier has prevented anyone with half-blood from exiting the sanctuary since then.
Echidna’s greed for knowledge would then make her continue using the magic crystal in order produce Ryuzu Meyer replicas to experiment on immortality. This continued till the time she was swallowed by the Witch of Envy Satella (and her soul was sealed by the dragon Volcanica).
After Echidna was sealed, the Sanctuary was under the care of Roswaal family. However, over time, the village deteriorated and its inhabitants became more and more alienated. Without knowing that the situation regarding demi-humans had changed to a certain extent outside, the ones trapped in the Sanctuary continued to be ignorant.
In order to break the barrier surrounding the Sanctuary, one has to partake in the trials that are carried out in Echidna’s tomb. If successful the barrier will be broken and the demi-humans trapped inside the Sanctuary will be free to move anywhere they wish.
At Roswaal’s behest, Emilia decides to take the trials in order to free the demi-humans trapped in the Sanctuary.