#dieinthedarkness is not a bad hashtag though likely to long to catch on. You could use #deathcult instead which is a direct metaphor and comment on the outcome of neo-liberalism and it's seeds (post modernism, post truth etc).
It's a cult that is going to displace and kill billions of us. Good simple stuff.
Ps. We are calling them hevay metal fans which is not a bad thing if they search for the hashtag.