Eternal Flame of Ignis Progressus:

The wielder of this artifact gains a +4 to religiously convert, reduce the cost of a tech, or change a religious tenet. This bonus grows by +1 each time the wielder sacrifices a number of Wood or Food, in any ratio, equal to twice the current bonus which resets any session two or more resources aren't sacrificed for this artifact. (Current Sacrifice: 0/6) Once the counter reaches +10, the artifact is automatically destroyed and turned into an incredibly powerful one-use artifact called the Eternal Inferno of Progress. This artifact cannot be upgraded, reforged, or wielded by someone who does not adhere to the faith of Ignis Progressus.