You'll find fox dens all over the map.
These lead you to Inari Shrines.
You'll notice a Fox that runs away when you approach, follow the Fox to the God of Natures hidden shrines.
The first four sets will unlock the last 4 charm slots needed to complete this trophy. There's enough Inari shrines to get this on the starting part of the island during Act 1.
As for charms, they can be unlocked by completing main missions, side missions, taking control of Mongol territory and in some instances helping civilians whilst travelling saving them from Mongol slave groups.