Relations between Christianity and pagan gods

I am usingsomething like the Ars Magica setting for Dungeon Fantasy and I am interested in what people think about the relationship between Christianity and the pagan gods like Odin, Zeus and Celtic pantheons. In this setting Christianity holds Dominion over most of Europe but there are pockets of areas where the pagan gods hold sway. I guess the opinions of people could be that the pagan gods are false gods or fallen angels or they could be neutral like the faerie. I am not sure how the pagan gods would feel about Christianity however. Also I am curious about how the creations of the pagan gods such as the elves, dwarves, nyphs, leprechauns, etc would be be viewed. Would they be feared as demons or would people be suspicious of them or would they be accepted? Also how would the creations of the pagan gods feel about Christianity? Thanks.

Relations between Christianity and pagan gods