No one ever did a successful dark theme for Patreon, either they didn't work or only some elements were dark, because div ids and div classes change over time. Well, it took shit tone of patience and time(just look at the code xd) to create this and I will complete it someday. There's still bunch of shit unchanged because, well as I mentioned before everything changes.
UserStyles.world: https://userstyles.world/style/334/patreon-dark-theme-beta