So far I've played Demon Souls (The original Souls game that began the genre), Dark souls, Dark Souls 2, The Surge and Bloodborne.
I plan to eventually play Dark Souls 3, The Surge 2, Nioh, Nioh 2, Code Vein and Sekiro Shadows Die Twice.
So far I've got the platinum trophy for 3 of those games: (DS2, Bloodborne and The Surge).