Don't Mess with a Spatial Ability User

The protagonists start out incredibly powerful. The male lead is Pangu reincarnated, while the female lead gained authority over time and space before she was even born, growing stronger as she learned to wield it. This is my first book, and I haven't written it in much detail. The side stories feel underdeveloped, and I went straight into the main plot. The first volume covers the mortal world and the immortal realm. In the second, I plan to have the protagonist's spirit travel back to the modern world, where his golden finger won't be as powerful, and have him outsmart his way to the star core. The third volume will be about a war between planets. Although the male lead dies in the first volume, he'll still be there afterward as a fighter, probably more like a background character. I could actually expand on that, but I don't know how to write it.