so I have a campaign which I recently finished balancing, the simple explanation of the plot for BBEG 1 is the party starts out in a small town and once they enter one of many large cities they get a quest to save a woman from bandits (what they do in that quest is irrelevant) once finished they see a large being fly over the city and then an old man approaches the party with an ecstatic attitude who wants to learn more about the creature stating how it is probably a high priest of Aylvyde ( the god of corruption and chaos) mangled from the immense power granted to it. He then asks the party to get an ancient book to help him learn the location of an artifact that high priests were said to defend, after finding the book the old man tells them that it's located on an island off the southwestern coast of Marsten ( a province in the continent of segora ). The party then travels there and kills the high priest and then some other stuff happens that is related to BBEG 2