Many gods were relieved, but they were also solemn about the situation. It is because they have realized just how difficult it is to kill the ancient titans.
Gemmis had made it look easy, but they understood that it was anything but easy. The whole process had cost a lot of divine energy. The gods had provided an average of 10 billion divine energy to kill the six ancient titans. That is just to kill six weakened ancient titans.
The ancient titans will come back stronger than before. The gods can continue to donate divinity to strengthen Gemmis, but if one day they run out of divine energy to provide her in the thick of battle, they will be doomed.