The regent feared that Di Fuyi and the Devil King would jointly plot against him. Therefore, after Di Fuyi entered into the Devil Kingdom, he sent countless masters to have him assassinated, but each of them was unsuccessful. Not only did they fail to kill Di Fuyi, but the killers also did not even return.
Nevertheless, the regent did not dare to send the army to intercept him blatantly. After all, Di Fuyi's reputation was too good around the six realms. He literally had friends across the globe. Even the rulers in the Human and Monster Kingdom were his good friends. If he openly killed Di Fuyi, he would only be attacked by the other realms!