This would introduce a new construct, and new dwarf "types"(?), Priests, and Demigods. Once you designate a dwarf to be a Priest, they can build an altar for whatever god they worship (if multiple, you choose). After building an altar, at any time, you may designate a creature to be a sacrifice to whatever god that altar is for. Once that sacrifice happens, something good will happen related to the god. If say, it is the god of plants, then all of the plants in your farms instantly become fully grown. Also, if you sacrifice a Champion or Hero, there is a chance (10-30% ish?) that they will become a Demigod, with powers related to whatever that god's powers were, as well as a massive increase in stats and instant max skill in whatever weapon skill was the highest for them before being sacrificed. If, again, say it was a god of plants, then whenever said Demigod killed something, it would turn into a 2x2 farm plot with a random plant at full growth. Also, say, if it was a magma god, then that Demigod could not be harmed by magma, period. Also, just to alleviate worries, if a champion or hero doesn't become a Demigod, then their champion or hero status will be passed on to the next strongest non-hero or non-champion dwarf.
This may, however, not be viable considering I don't know what kind of gods are possible to be genned by the game.
Thoughts?