Honestly he should have become a majin after killing so many of them. Would have been more interesting than...
simply reuniting with his friends, who are all good guys and elated he made it. They changed the currency to his name and built a statue celebrating him. Unfortunately, one of his friends became king and gave him the posthumous title of Grand Duke; which would start an entirely new noble house and potential strife. Instead he changes his name and starts adventuring again.