Image: Sucker Punch Productions / PlayStationOfficial screenshot from Sucker Punch Productions / PlayStation.
Friend to All Raiders is the gold Iki Island trophy for finishing every Tale of Iki. That means all story tales, side tales and Iki's Mythic Tales.
Clear every tale icon on Iki Island, including side tales like A Helping Hand and Troubled Waters, and both Mythic Tales.
You stay on Iki until The Blessing of Death is done, so plan to clear side tales while you are there.