When you reach the Camp of the Forgotten and meet their leader Soichi, he will ask four small favors of you from his former comrades. Around E.D.N. III there are mementos that mean a lot to Soichi and he’d like to back. Luckily we’re here to help you out in this already easy quest as Soichi practically draws you a map to their location(s). You’ll also need the magnetic hook upgrade, but they provide all of that for you, so hunt away! Completing this quest chain is imperative if you’d like the Enhanced Vitality Player Upgrade (50% increase in health) and History Lesson achievement/trophy.
Memento 1: Juro Katsuragi (Silver Flask)
Head to Marshall’s Gorge, the lone area with a looming electrical storm in the distance and shoot your winch to the designated area. As soon as you land, head into the adjacent cave and down, down, down the crevices ahead of you. Eventually you’ll come across a magnetic hook launch point, so launch away. It will lead to an air duct which opens into a command center. Scour the room for a computer desk where you’ll find Katsuragi’s audio log and silver flask.
Memento 2: Lagan Cherupara (Knight Chess Piece)
Now that you’ve climbed back out of the icy crevices, head into the power plant nearby in Marshall’s Gorge. Fight your way back to the same area with the crates and decrepit bridge. You’ll see a magnetic hook location nearby, so shoot it and shoot up to its location. Warning: you’ll be swarmed with a bunch of Tarkaa that are hatching, so deal with them and then make your way down a level. You’ll find the chess piece and audio log across from one another. Halfway there…
Memento 3: Colonel Mason Pickett (Rusty Dog Tags)
Colonel Pickett’s memento is in the dead center area of Pickett’s Folly on an offshoot island with some Akrid. Make your way to the small collapsing tower and look north/northeast for another magnetic hook lock-on. As you drop down you’ll find Pickett’s rusty dog tags, but don’t leave quite yet; head down another level and get his audio log too.
Memento 4: Silvia Herrera (Gold Brooch)
While still in Pickett’s Folly, head in to the Security Installation nearby and as soon as you’re done with the enemies found within, look to the right for your last magnetic hook leading to a memento. As you drop in, you’ll discover a sad site and your audio log and golden brooch memento near by the Halberd gun.
That’s it you’ve done it, you have collected all of Soichi’s mementos, so return them to him ASAP and earn your Enhanced Vitality Player Upgrade and achievement/trophy.