Mythic Tales are side quests built around old Tsushima legends, each one sending you after a lost technique, armour set or weapon. They hand out some of the best gear in the game, and none of them can be missed, so you can clear them during the story or after it.
On Tsushima, a wandering musician named Yamato tells each legend. You usually hear about him first from a rumour, a peasant or a journal hint, then ride to wherever he is playing. Sit and listen, and the tale plays out as ink paintings before the quest begins. On Iki Island the two tales come from storytellers at survivor camps instead.
Every tale ends with a reward you cannot get elsewhere. The Heavenly Strike, the Dance of Wrath and the Way of the Flame are combat techniques. The Curse of Uchitsune gives you the Longbow. Gosaku's Armor, Tadayori's Armor and the Kensei Armor come from the other Tsushima tales, and the Iki tales give you the Sakai Horse Armor and the Sarugami Armor. Most also grant a moderate Legend increase.
The Heavenly Strike opens right after the Prologue. The Curse of Uchitsune and The Legend of Tadayori need the first tales of Masako, Ryuzo and Ishikawa done. The three Toyotama tales open after A New Horizon in Act 2, and The Undying Flame waits for Honor and Ash in Act 3. On Iki, Kazumasa's tale needs Journey into the Past and Riku's needs A Raider's Return.
The Legacy of Kazumasa SakaiThe Legacy of Kazumasa Sakai is an Iki Island Mythic Tale about the lost armour of Jin's father's horse. It starts at a survivor camp near Zasho Bay and rewards the Sakai Horse Armor, which makes your mounted charges far deadlier.
The Undying FlameThe Undying Flame is the last Tsushima Mythic Tale, at the foot of Mount Jogaku in Kamiagata. You climb the freezing mountain from fire to fire and learn the Way of the Flame, which lets you set your katana alight with Incendiary Oil.Tales of Iki
Tales of Iki is the story of the Iki Island expansion: nine main tales plus a set of side tales on Iki. Finishing every Iki story and side tale, along with the Iki Mythic Tales, earns the Friend to All Raiders trophy.
Raider Memorial Archery Challenge
Raider Memorial Archery Challenge is a short unwritten tale in southern Iki Island. Wear Tadayori's Armor in front of a raider groundskeeper and he dares you to shoot seven lanterns. Win and he gives you a charm.