Who is Marethyu?

Answer 1

He is a mystery man who is actually the immortal mastermind behind what happens in the Alchemyst series.

Though, personally,I believe he is a wizened Josh,the sun twin. They both are blonde with blue eyes. Josh hates snakes, and in Marethyu has no snakes in his realm.Also, Josh wanted to create a world with creatures long extinct, and that is exactly what is in the Hooked Ones realm. Plus Josh fights with his left, and Marethyu has no left hand,possibly out of guilt.