AbdulAlhazred
Legend
August Derleth became the 'owner' of HPL's material, and he simply was both a crappy writer, and really hammed it up. He published a bunch of his own stories, and those of other writers in the genre, as well as republishing HPL's works very selectively. He is basically 'Mythos Lite'. He took certain references in some of the stories and recast the entire thing as a sort of 'battle of good and evil' where the 'Elder Gods' are sort of 'good guys' who once defeated 'The Great Old Ones' and locked them away. These 'Elder Gods' are still basically uncaring (humans are less than ants to them) but they will grant you power to fight the bad guys, and their signs and tools are a sort of 'good magic' you can invoke.I mean, maybe that's the issue? A lot of Mythos writers are kind of incredibly terrible and don't get Lovecraft, especially ones from the 1990s and before. The newer generation tend to understand-but-modify, but a lot of '90s and earlier non-Lovecraft Mythos stuff is just like bad fanfic frankly.
I would suggest entirely ignoring anything Derleth wrote, and a lot of what he published that was written after HPL. Most of it is junk. I mean, it might make a decent game of pulpy action. I'd say something like a less sci-fi version of EE Doc Smith maybe, where the PCs are helping to fight the Great Old Ones and keep them locked up, and agents of the Elder Gods, though quite dangerous and having little care for humans, show up to help now and then (at least maybe dropping a Star Stone or two around). It isn't Cosmic Horror though, not at all.