Re:Zero kara Hajimeru Isekai Seikatsu - Daiyonshou - Seiiki to Gouyoku no Majou

From Yen Press:
On to the next stage: The witch’s tomb, known as the Sanctuary. Determined to release Rem from a mysterious slumber, Subaru and Emilia return to Roswaal’s manor in search of clues on how to reach the Sanctuary, the secret location to which Ram and Roswaal escaped. But the way there is fraught with the unexpected. Especially for Subaru, who finds himself in the company of a curious figure. A new chapter begins, and with it, a new adventure.