Board Thread:The Heroes of Olympus/@comment-33225905-20171007091436/@comment-31481772-20171010131557

This is harder than I imagined!

Greek: Phobos/Deimos (They seem to have inherited bad traits from both their parents. However, they did help Piper and Annabeth in Blood of Olympus. I am not mentioning Zeus, Hera or Ares because I actually like their Roman versions.)

Roman: Janus (Not for his powers, just for how he behaved in Battle of the Labyrinth)

Egyptian: Isis/Serqet (I just like the others more. Isis seems to be more obsessed with power than Nekhbet, and that's saying something. I also found her to be obsessed with the letter of the law, rather than its spirit. Serqet didn't help the Kanes or Ra much in the battle against Apophis. Even the former antagonists Set, Sobek, Nekhbet and Babi contributed more.)

Norse: Heimdall (Riordan's version, that is)