MTL - Open the Simple Mode After Wearing the Book - Chapter 2 nightmare

Ajax was an orphan who survives a massacre along with his friends but unfortunately gets separated from them.

Fortunately, after a turn of events, he successfully gains a system which helps him increase his cultivation, but doesn't know what it is called.

But he knows one thing for sure, this system is very powerful and helpful in taking his revenge.

“Whoever you are, I am gonna find you”, Ajax mumbled himself with a disgruntled expression.

In a world where Summoning of an elemental spirit is done through a dream when they are 15 years old, Ajax with the help of a system and his summoned spirits sets out on a journey to seek revenge against the mastermind behind the massacre.

He rose from abjection and achieved eternity in glory.
He embraced the prettiest beauties and killed the strongest opponents.
He was able to shift the clouds into rain and cover the sky with one hand.
He could overrun the entire world and go anywhere as he pleased.
He pacified wars and held the world in awe.
He was matchless in the world.
However, his hair turned white overnight for his beloved woman and he was on the verge of death.
He was surrounded by enemies who were trying to take his life.
He struggled his way to become mighty and fought for everything he cherished.
For this age, he was the only king of the Dark World.
His name was a byword for might.
As a man living in the world, his only ideal was to pursue brilliance.

- Description from Novelupdates

Stella Wilson, a nice rural lady who went to New York to pursue her Veterinary degree. Also, she works part-time as a pet sitter to a three little cats. Her boss, Alice Adelson instructed her to keep the cats away from the next-door neighbor Sebastian, the billionaire. An Alice cat, however, managed to escape from Stella's care and make the way to Sebastian's property, where caused her trouble. Stella is caught by Sebastian while trespassing his property.Sebastian informs her that she must keep the cat away or else he would punish her. Sebastian has already made the decision that he will going to own her and has stated that she will be responsible for the payment. But it's not in monetary value that he's looking for.

Pressured to get married or lose her father's financial support to pay for her mother's medical bills, Joanna Baker, the illegitimate daughter of the Baker family, is devastated when her boyfriend chooses another woman over her on their wedding day.Joanna, feeling distraught, witnesses a man in a wheelchair proposing to his girlfriend at a restaurant. The girlfriend's rejection and subsequent insult for his disability left everyone stunned.Feeling a shared sense of betrayal, she approaches the man with a vengeful proposition.“Excuse me, sir. Your girlfriend dumped you, and my boyfriend chose another woman over me. Let's get married for six months and get revenge on them.”What will Joanna do when she finds out the man she proposed marriage to was none other than Alexander King, the heir of the wealthiest family in NYC? He was also the cold CEO of King Multinational, with a hidden identity, Salvatore Black, whose name caused even presidents shiver? Has she just signed a deal with the devil?