@thewriterofyourfate Hey there! That's a totally legit question. It's probably really confusing with so many books.
Anyway, Romancing the Son of Heaven is the prequel to Oh. My. Fate?! so chronologically, it comes before OMF. (OMF basically slots into the story at almost the very end of RSH.) I've tried to write both of them in a way so that you can read them without knowing the other.
Personally, my suggestion would be to start with OMF, and read until you at least finish volume 3 (Wandering Cultivator) since by then, you'd have a better grasp of the general way the story world works. You may want to read on until you hit volume 5 (Secret Realm Prisoner) if you like piecing details together yourself as RSH can spoil some things in that volume.
Alternatively, you can also start with RSH if you like to read things in chronological order and don't mind already being in on some secrets by the time you hit OMF. The series isn't completely finished though and I only update it once a week on Sundays so you might have to wait a little longer until you'd get to the part where you can switch over to OMF which, again, is in the last volume only shortly before the grand finale.
Apart from these two, there is the Oh My, How Extra! book which is a collection of some specials I've written over the years. I'd suggest to only touch that one after volume 3 as well since you'll only meet some characters by then. Some of the extras are also set after the story but they usually don't spoil anything major. Like, you'll know the main stories are all HEAs but I suppose that doesn't come as much of a surprise xD
Anyway, I hope that helps! If you want me to clarify anything further, just ask. I'm always happy to help! :)
