His defence

Yang Yeo slowly sat beside him on the sofa, a frown ceasing his eyebrows. 

"Did you even think for a minute before killing them?" he asked in a calm voice

Sung-ho sighed subconsciously, his eyes were still closed. Honestly, he hadn't think twice about what to do with Elrod after he heard what that monster did.

"I did," he lied smoothly.

    She was his mother's best friend, also the teacher who had taught him for almost seven years. Due to being a Mafia's son, Sung-ho had to be homeschooled with Yeo and she was not only an amazing teacher, but also like a family member to them. Sung-ho was cruel and merciless to his enemies, but he would protect the people he loved until his last breath.

Though he failed to do that

And he was angry and frustrated at himself. After hearing what Yeo just said, he was continuously questioning himself whether should have thought more about killing Elrod's men or not. Did he feel guilty? No, he did