it's interesting to me that I've seen a few people say nine sols feels harder than Sekiro to them; I haven't played Sekiro, but I've played Dark Souls and I remember hearing people say Sekiro was particularly difficult among From's Soulslike catalogue when it released.
To me, Nine Sols feels significantly less difficult than Dark Souls. I'm not sure how much of that has to do with my relative capability with 2D vs 3D action games or my relative comfort with parrying compared to other players. just kind of interesting 2 me!