The tomb keeper pretended not to hear the Martial Dao Prime Body's question and only said, "The combat strength of the two of you in the Emperor realm can indeed be said to be at the peak. However, there can only be one Great Emperor in the medium chiliocosm."
"Apart from the two of you, other peak Emperors have a chance to attain their Daos as well. Without becoming a Great Emperor, it'll be difficult to fight against the Heavenly Court."
The tomb keeper was clearly avoiding the question of the Lord of the Netherworld.
Given the identity and background of the tomb keeper, if he did not want to answer, it would be useless no matter how much the Martial Dao Prime Body asked.
Furthermore, the Martial Dao Prime Body could already sense that the tomb keeper had the intention to leave.