To the Lord of Advent Heaven, even if Feng Du became a Great Emperor, he was not a threat to him or the Heavenly Court.
Furthermore, Feng Du's method of verifying the Dao to become a Great Emperor was not through verifying the Dao in the medium chiliocosm.
Instead, he severed Three Corpses before fusing them to transform into the body of a Great Emperor. Thereafter, he would inject his Great Emperor-level Essence Spirit, allowing his combat strength to reach the level of a Great Emperor.
To the Lord of Advent Heaven, the true threat was the Martial Dao Prime Body!
He had just advanced to the Emperor realm and already had combat strength comparable to a Great Emperor.
If he was allowed to grow, there was a high chance that he would severely injure the Heavenly Court!
The Lord of Advent Heaven did not care about the lives of the living beings in the medium chiliocosm.