Yang Qi dominated Lady-Princess Silvermoon, and used the Grand Emperor's Pagoda to completely overwhelm the vital energy of the city itself.
He wanted to refine the entire city, by placing the thing inside the Grand Emperor's Pagoda.
The remaining three War Gods were incapable of escaping, and were also sucked inside. Yang Qi didn't kill them. Instead, he would imprison them and save them for later use. It was the same with Lady-Princess Silvermoon, whom he could theoretically sell back to the Sky-Heaven Dynasty for a hefty ransom, as well as all of the citizens of the city.
Raging sagefire swept through every house, street, and corner of Silvermoon, subjugating all of the spell formations, and leaving Yang Qi’s mark on them.
Then, the fire continued into the foundations of the city, where countless precious materials of heaven and earth lurked. In the blink of an eye, that treasure was snatched up and pulled into Yang Qi’s pagoda. Some such...