Harpy's Feather Cloak
The fate of those that don the Harpy's Feather Cloak has not been good, Paladin.
But if you still want to seek it I shall help you. Everything I have read or heard
about the Harpy's Feather Cloak points in the direction of the harpies of Oceanus Notos.
If you seek the Cloak, I would suggest that as a starting place, although where it will lead you,
I do not know at this time.
I will tell you but one thing, to obtain the harp they sing.
Remove it when the Sky holds true...lest you be a warrior true.
The Sky will make it easiest yet. This will be your best bet.