Bandai Namco has announced that the Dark Souls franchise has moved 25 million units across all platforms. That includes some contribute from Dark Souls Remastered on Switch, although we don't know the actual figure. Check out Bandai Namco's blurb on the milestone below.
Action RPG series “Dark Souls” was another joint development project undertaken by FromSoftware and Bandai Namco Entertainment. Since its initial release in 2011, the series has continued to turn sales, with a cumulative shipped total exceeding 25 million copies(*). The latest in the series, “Dark Souls Remastered”, enjoyed a simultaneous worldwide release in 2018 and is supported in 13 languages. Seeped in dark fantasy, the series allows players to experience the tension of dungeon exploration and savour the thrill of overcoming adversity, receiving worldwide praise for its mix of real-time multiplayer and asynchronous online elements that help players feel one another’s presence even during single player.