I write stories about dark and complex characters.How come we make it more intriguing to readers ?

I want to write 4 th story as dark concept. Did people enjoy main character being dark?

My story style is portraying main characters into dark, complex and twisted but some times I feel like can it always work. How can people admire dark charcters more? What to do on this writing making them to connect to my readers? Because I feel like now my story is getting less attention.