The mafia lords unknown son

Thirty-two-year-old Park jaein is evil, he has no humanity and is the king of the under world.

The saying "even the devil was once an angel" was all a lie, Park Jaein was born evil.
With a domineering personality, he was disliked by all in his childhood and teen years, all except one the innocent,shy "Kim Yerin".

Park Jaein was simply misunderstood by his actions, so when fifteen year old Yerin showed him love and care he fell deeply in love with her and proposed that she was his girlfriend.
Months of dating the two teens were inseparable, Jaein changed, he knew that as long as Yerin was with him nothing else mattered.

So when fifteen-year-old Yerin disappears, sixteen-year-old Jaein's personality takes a turn for the worse,he becomes a monster.

sixteen years later, Jaein is out of control and anyone who causes the slightest inconvenience to him dies.

What if Jaein could be saved and his saviour a sixteen-year-old orphan "Park Jaemin"