Oh, there IS a warping system, though it was really not obvious, I easily missed it when I explored the Grave of the Hero because I didn't know where was the jumping tool at this time and I forgot to re-explore the grave once I got the zephyr boots until I read about a "dark mirror in the Grave of the Hero" in the walkthrough.
My point is: This is an important tool and it is easily missed, you should make sure that everyone finds it, you could make the hermit give a side quest "Find the Dark Mirror" at the same time as he gives the quest about the 4 titans, after he talks about the titans, he could add that there is a tool which might help the heroes in their travels, he could talk about a fabled mysterious mirror which was said to allow its user to fast travel from a place to another which was rumored to be in the legendary Grave of the Hero.