Zak is Kur. He does not know that until it is proven when Doyle recovered and brought back the Kur relic used to detect Kur. It was stolen from the Nagas, then Fiskerton (Fisk) stole it. It was proven in Antartica when Argost was going to intercept them.
first thought that Kur was the creature or cryptid that attacked Zak and his family. Argost also thought it was Kur, instead Zak was.
But like, how did Doyle actually know how to recover it, and how did the Kur relic actually recover itself by using magic?