Wang So is introduced as the fourth heir of Emperor Taejo, but he is far from a privileged prince. Early in his life, he was physically and emotionally scarred by his own mother, Queen Yoo, who gave him a facial scar during a dispute with the King. This physical mark forced him to hide behind a mask, leading to his ostracization from the royal court and the public, who branded him with the derogatory nickname .
The turning point is the death of the 10th Prince. So holds his dying brother, covered in blood, and looks up at Hae Soo. In her eyes, he doesn’t see love. He sees fear. The same fear he saw when he was a masked child.
Here is why the Fourth Prince’s journey is one of the most tragic arcs ever written. scarlet heart ryeo wang so
To secure his reign, he must kill his enemies—many of whom are his own brothers. He becomes the blood-soaked king everyone always predicted he would be. The tragedy is that he does it to protect Soo , but the violence pushes her away.
The rain scene. The “I love you” whisper in the barn. The way he looks at her like she hung the moon. This is what makes his fall so agonizing. He didn't change for power. He changed for love . Wang So is introduced as the fourth heir
But the tragedy of Scarlet Heart Ryeo is that the system corrupts the innocent. As his brothers die or betray him, and as the cruelty of the court intensifies, Wang So realizes that kindness is a weakness. He ascends to the throne not out of greed, but out of a desperate need to create order and protect the woman he loves—even if that means becoming the very thing she fears.
By the time he becomes King, he has hardened. He executes political enemies without blinking. Yet, Lee Joon-gi’s performance ensures we never lose sympathy for him. We see the exhaustion in his eyes. We understand that every drop of blood spilled is a piece of his soul he is sacrificing for the stability of the nation. The turning point is the death of the 10th Prince
Years later, fans still debate whether Hae Soo should have stayed, or whether Wang So became too cruel. But there is no debate that he is one of the most complex, layered, and unforgettable characters in K-Drama history. He was the scarlet heart of the story—beating, bleeding, and ultimately, breaking.