Bandai Namco Entertainment filed a trademark for “Nightreign” in Japan on October 24th. The document was released on November 5.
Currently, the company does not have any upcoming games with “Nightreign” as the title or subtitle, so it is possible that this trademark is for an unannounced game. Bandai Namco Entertainment has a tendency to trademark game titles and subtitles before they are announced, in some cases long before they are announced.