"It seems some force is interfering with the transmission of ancient memories. I can only roughly discern that the ruins of the Eden District have been fragmented, with most of them having subsided into certain areas of the Dark Territory due to geological changes.
Currently, only six surface ruins can be tracked.
Lady Oksana went there three times before her death, entering different ruins each time. However, she did not go there to collect any kind of power; she simply wanted to retrieve those erased memories.
I can confirm that before being murdered by Archduke Charlemagne and Archduke Salockdale, the lady had already remembered many memories.
But that was by no normal means.
The situation you are concerned about did happen. In the final stages of her life, Lady Oksana showed signs of being polluted by subspace. She could hear a shadow called 'Original Sin' issuing her various invitations.
