My dude, best I can describe Berserk as is grimdark fantasy along the lines of Soulsborne games, though it predates them by a large margin.
The series had its own Lovecraftian elements in the form of a group of malevolent entities known as the God Hand and the corrupted humans that they help empower, called apostles.
It follows a mercenary who gets swept up in supernatural events and ends embroiled in battle against the God Hand and their apostles, as well as all manner of other supernatural horrors.
The world begins not unlike our own during the dark ages, very mundane with supernatural events being rather rare, but is progressively transformed until the veil between the spirit realm and our reality is torn asunder.
If you like the lore and style of the Soulsborne games, and don't mind anime/manga, you'll probably like Berserk.
The 2016/2017 anime covers the soulslike arcs, though not very well and it made some poor design choices with the art, but if you can past that, it's not bad.
There's also an older anime that covers the "Golden Age" arc, as well as a set of 4 movies that do the same. Both have their pros and cons, but neither is bad.
The manga is outstanding if you like the media, But it can be a bit jarring and tedious if you're not used to its formatting.
If anime/manga isn't your thing, then it might not be for you. But if you give it a shot, you'll see a ton of things that inspired elements in the From Software games.