While we suspected Age of Calamity has had an impressive sale, Koei Temco substanciated this by revealing that as of December 3.5 million units have been sold worldwide. This makes it the best-selling Musou game ever.
Though not at the same level as Breath of the Wild (9.4 million currently), being a prequel to this game definitely helped. Unfortunately, its sales numbers are dropping quite rapidly after its initial launch period.
Source: Nintendo Life, Statista
