He has 2 solutions! Conquer everything, cull the corrupted, disarm them, make some sort of federation where people can choose how to live! Or be a constant threat with small sporadic attacks along a border for decades! Humans will not change in few years and definitely don't have the population to afford a prolonged war, something that he needs, to give time for them(the leaders) to change! So only the first option is viable imo!