How rare would you say the fated slayer of the damned title is?

I’ve never seen anyone use it, I would assume it’s pretty rare since the last week of the fate of the damned was the hardest. I was lucky enough to get everything from that event including the titles, but I haven’t seen many use the titles. The equipment and outfits I’ve seen a little, but not the titles. On top of the fate of the damned titles, what else would you say are some of the rarer titles?