The only Soulsborne I have played so far is Bloodborne and i loved it so much that I'm afraid I won't like the other ones. It was hard, but luckily other people can join you to help - something that Sekiro doesn't have.
I also played and finished Halo Combat Evolved on legendary, which I usually don't do for shooter games, but it's really exciting and a proper, but fair challenge.
Number 3 would be Doom Eternal. Burnout 3 had a few really hard races.
I always thought Legacy of Kain games had huge difficulty spikes, but I'd love to see a Remake of all the games now that Square Enix sold the IP (plus Tomb Raider and Deus Ex)
Max payne 1 was hard. Lot's of early rpgs and shooters were hard (Doom 2, quake, gothic) or later ones like No one lives forever, Project Igi 2 and Return to castle wolfenstein.
I was never good at strategy games or card games, so they are all hard to me.
In multiplayer: Fifa 21
seasons mode is EXTREMELY hard to me, I haven't won Div 1 for the first time since I started playing Fifa Seasons in Fifa 14. Yesterday I got Fifa 22 on Ps+, so maybe if somebody wants to play, hit me up