Mercury

Mercury is one of the four magical resources (along with Crystal, Gems and Sulfur). Mercury is required to construct several buildings and to hire Devils and Arch Devils, Ghost Dragons, Phoenixes and Azure Dragons. The primary source of mercury is the Alchemist's lab, which produces 1 mercury per day for its owner. You can also find mercury scattered around the land in small amounts (3-6 units of mercury per resource stack).

In Inferno and Conflux towns, you can build a resource silo, which will bring you 1 unit of mercury per day.

Rissa the Alchemist is able to produce 1 additional unit of mercury per day for the kingdom she serves. Also, any hero equipped with the Everpouring Vial of Mercury produces 1 unit of mercury per day (Rissa would produce 2).