i don't understand who exactly is aogi and utsugi, what their roles are etc.. anyone?

Go check out the authors' account @onikushock2, you'll instantly have a clue on who they are based on their illustrations

i think utsugi is the prince/king by the way they called him your highness and he say that all of that because of him so maybe he the first fangs or vampire and make his soldiers became vampire to and they likely be megi, aogiri (cuz megi call him captain), sugi and umesaki (my guess) they likely the first vampire but its just a guess tho