I’m Obviously Overpowered, Yet Everyone Thinks I’m Useless

[One-on-one power fantasy + devoted couple + mystery + smart characters + no golden finger or pocket dimension, heroine reaches the top from the start through her own hard work]

Note: Any inconsistencies early on will be explained later!!!

Su Shiling was a little ghost on the verge of vanishing when, by chance, she unexpectedly possessed the body of a useless young heiress from a powerful family who had already died.

Useless?

Just a pretty face?

But after Su Shiling was exiled for three years, everyone discovered that she had not only returned safe and sound from the Demon Clan's City of Desire, but had also become its new ruler.

“Useless? Sorry, are you sure you haven't got me mixed up with someone else?”

That was what Su Shiling said after returning from the City of Desire.

To find the real killer of the original “Su Shiling,” she had never stopped investigating in secret. Along the way, she also gained an exceptionally capable sidekick.

But gradually, Su Shiling discovered that her sidekick had an unusual identity: he was none other than the infamous and ruthless Ghost Lord of the Ghost Clan. What was she supposed to do about that?

Still... looking at the well-behaved, adorable young man in front of her, Su Shiling couldn't help wondering whether the rumors were wrong or he was just that good at putting on an act.

Whenever trouble arose, her sidekick would tell her, “I'll take care of it. Don't get your hands dirty, Sis.”

When he got hurt, he'd look so aggrieved and ask, “Sis, does it hurt you to see me like this?”

Oh, well. Having a sidekick like this around wasn't so bad, was it?

[Every character who appears in this story has a purpose, which will gradually become clear later on. This is my first time writing this kind of story. It's called a mystery, but if you look closely, it's not all that rigorous, so I hope you can read it without overthinking qwq]