After the Fake Young Lady Stole Everything from Me, I Became the World’s Sweetheart - Chapter 458 - Four-Hundred and Fifty-Eight: New Birth

A normal office worker, Toru Minasuki, was swallowed up by a dimensional fissure and reincarnated into a different world. Upon reincarnation, Toru was given a [skill board] by God. Make the most of it to acquire all the necessary skills! Even though he is an “inferior person,” he’ll make his way to the top!

In the waves of steam and machinery, who could achieve extraordinary? In the fogs of history and darkness, who was whispering? I woke up from the realm of mysteries and opened my eyes to the world.

Firearms, cannons, battleships, airships, and difference machines. Potions, divination, curses, hanged-man, and sealed artifacts… The lights shone brightly, yet the secrets of the world were never far away. This was a legend of the “Fool”.

- Description from novelupdates

She was used by her boyfriend to trap someone. Unexpectedly, things did not go as planned.

She, a renowned assassin of the 21st century, actually crossed over to become Su Manor’s most useless good-for-nothing Fourth Miss.