Even after the end of his trial, Rein's work in this world was not completed. After reaching an agreement with Machina, Rein and everyone else first returned back to the base camp to give everyone the good news.
While Rein and the others were busy going deeper into the core of the danger zone, the fight between Rein's army and the insect army had reached an all-time peak in terms of intensity. Millions of insects died and some of the humans also breathed their last. So the news that they had won the war and had managed to save the world was a news of relief for all of them.
There were a few people who were not so happy that these bugs had now become their comrade but after learning that the Will of All Chaos was actually immortal, they had to accept that this was the result that they could get.