If you are looking at free overhaul mods like the Modern Dark Souls III Experience , they introduce significant mechanical shifts:

: Community reshades and configuration tweaks can unlock unused color grades or increase contrast and light shaft prominence. 🗡️ Core Game "Deep" Features

For those playing the standard version (which includes DLCs like Ashes of Ariandel and The Ringed City in many repackaged versions), the "depth" comes from its RPG systems:

: Adds a "poise" system similar to the original Dark Souls and introduces "perfect block" mechanics (Sekiro Parry).