It seems like at the end of Faust II, he has realized what he should do. Shortly before that, he kills humans on his quest to help humanity. So what exactly is his new purpose, except that he has given up his power?
Was his whole journey just about experiencing different forms of things he would think he enjoys, to realize they aren't what he wants, and is happy just existing?
Or in other words, if he knew what he knows now at the beginning of the book, what would he have done? Continued his research? Nothing at all? Something completely different?