Here are three tier lists I made ranking the characters, ships and books from the Percy Jackson and Heroes of Olympus series. These are just my opinions, there is no right answer. Feel free to share some of your thoughts!
These tierlists were made by someone on Tiermaker. I added and re-named a few of the categories and chose were to put everything. Sorry about the poor quality, if you don't know what any of the pictures are or the category names just ask.
