Nathan ended up getting called by Vivian. The reason was obvious. He was lectured for an hour by the dryad. However, he knew they had recognized his competence and acknowledged him as Vivian's disciple.
In the end, Nathan promised not to cause massive destruction to nature. In exchange, they would also help him as Vivian's disciple.
Of course, he had to give a report about what happened on the island and about this alien queen. Still, the main threat would be the mutant. If they could actually produce a lot of mutants, it would be dangerous. Unlike the aliens, humans who had turned into aliens didn't have a core, like how they experienced it on the front line, so killing them didn't really benefit people.
As such, all the bodies on the island were brought back for identification and research, trying to figure out what this mysterious organization was trying to achieve.