Nightreign only supports 1 or 3 player modes, the mod lets you play with just two players.

As a somewhat busy adult with work and kids, finding time to play together with friends is kinda hard. We have some set times a week where we try to play together (but we have more than 3 players) and we often squeeze in 2 player game sessions when possible. Nightreign only supporting exactly 3 players for multiplayer didn’t really work for us.