Bandai Namco Entertainment has filed a trademark application for Nightreign. This happened on October 24 in Japan, but the official statement was made public only now.
At the moment, the company does not have any announced projects with the title or subtitle Nightreign, so we can assume that the registration refers to a new, unannounced project. Bandai Namco has a history of registering game titles and subtitles ahead of their official announcement, sometimes well in advance, so fans should expect further news to find out what might be hidden behind the title.