This is a Side Tale in the Iki Island Expansion for Ghost of Tsushima: Director’s Cut. These are completely optional but if you’re aiming for all Trophies, must be completed towards that goal.
Travel to the Ghost’s offering site
Make your way to the Kemono Trail to the southwest of Fort Sakai to find a group of villagers discussing a so-called Ghost of Iki, an imposter to be sure. Speak with one of them to begin the Tale and then, after hearing some choice details regarding this Ghost, make your way to the river to the southwest of your current location.
Once you reach the offering site, close to Kidafure Battleground, take the time to examine the three objects to trigger Jin to wait until nightfall. Once you regain control, survey the area and then once you locate the “ghost”, follow him to discover a trail he has left. Examine the ground and then follow the tracks to the northwest to meet someone who works for the “ghost” who informs you that his master has been caught by bandits.
Rescue the Ghost of Iki
The bandit camp can be found to the west of your current location, make your way there and you’ll find some bandits at an old, abandoned hut. Defeat them via any means necessary and the free the “ghost” who turns out to be Jin’s old friend, Kenji. You’ll now need to lead Kenji back to the campsite you just arrived from, this is far easier if you decided to deal with the enemies before heading in to save him, allowing you a casual stroll back to the campsite.
Once you arrive, you learn that Fugu is nowhere to be seen, so Kenji suggests heading to their agreed meeting place. Follow Kenji and you’ll meet up with Fugu where you’ll learn that Kenji has some expensive debts to pay with the Viper. Mount up and follow the pair of them to Viper’s Den and once you arrive, follow Kenji to meet and speak with the Viper. You’ll gain two choices in the following conversation, choosing the Defuse options will allow you to skip a Duel that you can’t win if you pick the Confront choices.
Collect the Viper’s navigation charts
Regardless of how you reach this point, you’ll come to an agreement that if Jin can secure the Navigation Charts from the Mongols, he’ll grant Kenji passage back to the mainland. Leave this area and mount up, heading east from your current location until you reach the objective marker.
You’ll find yourself just outside the camp and Kenji will stay behind while you go to deal with the Mongols. If you don’t want to simply wade in with a Stand-off, begin by taking out the Archer on top with your bow. From here, head around to the ladder and climb up, using your bow to pick off the nearby Mongols. You should be able to deal with most of the Mongols in this area and should you alert any, you can leap down with an Air Assassination and then use your Ghost gauge to finish the last of them. With the area clear, head to the center of the search area to find the Navigation Charts on some wooden platforms.
Return to Kenji and speak with him and you’ll automatically return to the Viper, speak with him to hand over the charts and bring this Tale to an end.