There is nothing I hate more than fics where people are celebrating holidays that just would not exist in their culture. There is no Christ in FE, therefore there is no Christmas. Or people named Chris for that matter, though IS ignored that one.

Yeah, but by that logic, no FE script could never use the word "vandal". Or "Barbarian". Or "Berserker." Or have people named Rebbecca, Lot, Noah, etc. (all of which are FE characters, by the way). Personally, I don't see how Chris is such an oddball name compared to all those (although I will give you how wrong it would seem for actual Christmas to be celebrated in a fantasy world :P)