“ Temple of some malign being invites you warmly and offers help (curing,needed spell etc) for some minor sacrifice . Sacrifices must be everytime bigger to work - up to living inteligent creatures. Maybe you pay some other price,too...”
“ City, group, religion; every time a significant event happens to the city/person a new name will be given to signify the event. Could add the names to previous ones like a list of titles or could just be completely changed every time.”
“ Mining in a certain area turns all exposed skin (maybe just parts that are actively disturbing the chemicals that cause the reaction) of the those doing the mining to a dark blue color. Will wear off taking as many years/days spent in the mine.”