I am going to assume that most readers of Creating Fairytale are already readers of Tainted Fairytale, but for the benefit of the silent and/or new readers who are only interested in Baekhyun's love story, I've decided to write a brief summary (I tried, this is as brief as it gets) of TF which is very closely related to CF. You'll need some knowledge of TF before you can proceed with the early chapters of CF because they're not going to make much sense with all the time jumps. The subsequent chapters of CF will get better as it enters the post-TF era, which means it no longer has direct relations to scenes from TF.

[ Tainted Fairytale ]

The evil root of it all begins with a woman named Lee Hwi Yeon - born into poverty and has lived in the slums until the Bang family took her in. She then develops a relationship with the son, Bang Sang Min, and they have a daughter, Bang Minah, together. Their marriage is never registered and only Minah is registered under Sang Min's family records.

Hwi Yeon works for the Oh family as Sehun and Se Ryeong's mom's caretaker. Their mom is ill and bedridden, and requires constant care as Mr Oh is a busy businessman. Their family isn't exactly super wealthy, but they're definitely above average. Greed soon overwhelms Hwi Yeon and she becomes Mr Oh's mistress, often neglecting her duties as a caretaker as she spends her time seducing Mr Oh. The day Mrs Oh was gasping for her last breaths on bed, Sehun and Se Ryeong - 7 years old and 6 years old respectively - ran into their father's study for help only to find Hwi Yeon half in their father's arms. They lose their mother to illness and their respect for their father on the same day. Shortly after, Mr Oh is mysteriously involved in a car accident that leaves the Oh siblings orphaned. All of Mr Oh's properties went to Hwi Yeon according to his will. 

Years later, Hwi Yeon becomes the wife of Kim Dong Woo - a hugely successful and wealthy businessman who has a share in all kinds of businesses - and the stepmother to Kim HyunA after CEO Kim got a divorce. HyunA is 9 years old at this point, same age as Kris Wu (her childhood best friend and later on lover) and Se Ryeong. Sehun is 10 years old at this point but the paths of the Oh siblings and HyunA does not cross yet. Note that Sang Min is CEO Kim's most trusted right hand man in business. 

Kris has always felt negative vibes from Hwi Yeon, which was partly the reason why he spent all of his time with HyunA after understanding that the woman was her new mother. The years passed without anyone finding out Hwi Yeon's secret husband and daughter - Sang Min raises Minah all by himself. 

Come HyunA's sweet 16th, her perfect princess world faces danger when Sehun intentionally befriends her in att