Lore by Alexandra Bracken
Every 7 years the Agon takes place. It is a week long event when the 9 core gods of Greek mythology become mortal and are hunted by descendants of the Greek heroes. If a human kills a god in mortal form, they transcend and gain the god's powers.
Lore is the last descendant of Perseus, the hero who slayed the gorgon Medusa. Her family was brutally murdered and she escaped the Agon, or so she thought. An old friend returns and Lore is dragged back into the hunt.
Bracken might be best known for her Darkest Minds books. This stand alone takes a completely different take than those, but is still full of adventure. I will say some of the ideas/rules/beliefs of the Agon got a little confusing to me. And Lore can be an extra bit brash, but I was compelled by the world building and side characters to continue with the book. The ending is slightly anti-climactic, but I'd still recommend this, especially to any Greek Mythology fan.