The phrase "mortal realm" refers to the world or existence in which humans live and will eventually die. It emphasizes the limited and temporary nature of human life on Earth. Full definition
Alas, here in the mortal realm, that combination tends to be a total sugar and calorie bomb - not ideal for those of us trying to feel our hottest this upcoming Valentine's day. (abbeyskitchen.com)
Which your trade Stenpoint brings back into the mortal realm, depth wise. (sbnation.com)
Since there are, however, some democratic (or meritocratic, as suggested by @gerrit) elements to the governance of this mortal realm - election of moderators, and so on - one model to which SE could be said to bear a slight resemblance is the Democracy / Theocracy amalgam of Iran (with, admittedly, many differences, not least of which is that Wikipedia does not appear to be contemplating an invasion of SE to prevent us from getting nukes). (politics.stackexchange.com)