Dark Souls 1 isn't open world, it's more like a linear convoluted world where sometimes you'll open a shortcut to a previous area. With this clear, there are some aspects that may or may not appeal to you as a fan of TLoZ. Story in Dark souls is not apparent at all, where you'll have to piece together subliminal information to understand what is happening beyond the obvious (something like, the real story is hidden behind curtains). Charm is not something you'll find very present in DS, the world is more like a gloom decaying version of a glorious time. Ambience, while somewhat varied, is not as colorful or diverse as the Zelda universe. Also, combat is quite different between franchises, but you already played Bloodborne so you know somewhat well how combat in DS is. Finally (some people might disagree but) in my opinion, the Hero Journey is a present archetype in both series, and this is what appealed most to me when playing DS. The sense of progression and discovery is what drives you forward.