He certainly had a reason to be happy. These Space-corroding Sects were a type of Primordial Supernatural Sect, with a strange type of toxicity. They gathered together and sprayed venom, even a Lord of Heaven could not withstand it. Their Self-world would be eroded by this poison spray, and that was to say nothing of someone less cultivated than a Lord of Heaven.
Even if they were strong and their attack was fierce, when their space was eroded and broken, they had no place to survive. They suffered badly. To add, the Queen Sect did not possess any more plentiful intelligence, but her strength was enough to contend with a Genuine Immortal of the Venerable Realm. Some Queen Sects had evolved to even have the strength of a Lord of Heaven Realm, so it was very difficult for a Lord of Heaven to enter the nest of Space-corroding Sects.