此路是我開，欲從此路過，留下買路錢。

It's remarkable for the wife to kill the insane husband to prevent him from committing more bloodshed and uphold justice. This show borrows a lot of characters, martial arts, and subplots from Jingyong's various novels. The revenge arc here by I-dow resembles the revenge saga by Choufeng in Jingyong's novel, who finds out that the "villain" who killed his father turned out to be his remaining parent (here it's the mother, not the father), a variation on Oedipus.