The Leviathan System - Chapter 27: The Staff of Aleron

For the large sum of money to help her husband, she chose to be a surrogate mother covertly. Her sweetheart was out of trouble, but she became the woman of loose morals in his eyes. Misunderstanding, disappointment and sadness forced her to divorce the man she loved from the childhood.

When she was determined to start new life, another man burst into her life. “You are my baby’s mommy and you are my wife!” A big surprise hit her that her baby’s Daddy, the man she surrogated for, fell in love with her at his first sight.

His deep love convinced her to believe the affection of love again. Unexpectedly, her ex-husband returned to beg her recombination. One was her childhood sweetheart, and the other was the man who loved her and gave her hope for a new life……Facing the two men, what is her choice?
 

- Description from Novelupdates

I...AM...MOB CHARACTER!!!Sigh~My name is Samael, I was an office sla- I mean a worker who worked 9 to 5. It was a daily routine of monotony until one fateful day when I went home only to find my best friend with my girlfriend. Betrayal was the first thing I felt, followed by rage.And after taking ‘care’ of them, My surroundings changed…Looking at my reflection in a mirror, I noticed my appearance had changed. Gone was the face of the disgruntled office worker; instead, “SAMAEL ASHWOOD!!!” a character from a novel I used to read. But this wasn't just any character; I had become him—the sacrificial best friend of the protagonist who was betrayed and died in just the first two chapters.PROTAGONIST DIED!?[Heavenly Destiny System Initializing...][...]

She was a famous assassin who had killed important figures, but ironically, she was killed by her own lover.And when she thought she was dead, it turned out she was occupying the soul of a young girl who was tricked by her own family.'Because I have been reborn, I will take revenge on the people who planned my murder and also teach a lesson to the people who underestimated the girl whose soul I reside in!'However, things become complicated when she has to marry a cold man, whom she spent the night with.