Reward Board: 2,000a, 25 SP
Early in your trip through Chained Echoes you'll run across a girl, just outside the Fiorwoods, who is essentially the construct of a madman. She's left in the village of Iden after that, and you get no resolution on her story - at least, that is, until you reach the end of the game. That's where A Will To Live comes into play.
To trigger this quest you need to complete Chained Echoes, one of the main quests. Once that's done, head back to Iden, in the southeast of the Fiorwoods, and check out the tavern. It's right beside the Fast Travel Crystal, so you can't miss it. When you enter one of the villagers will tell you that Arlette, the girl in question, has gone missing. All they know is tha she's likely gone west, into the more dangerous sections of the Fiorwoods.
Leave Iden by the north exit and travel more or less directly west. There are a few clusters of enemies along the way, but by the time you reach this part of the game they will be no threat to your party. Upon arrival the team will find Arlette... aaaaaand she'll run away. You'll need to track her down.
(This part of the Fiorwoods is largely optional, and much more dangerous than the other sections of the woods that you explored much earlier in the game. If you need help finding items while looking for Arlette, this guide will get you started.)
Arlette is found next in the southwest of the Fiorwoods. To reach this spot from your current location you'll need to travel down the path to the northeast, past some Forest Wyrms, and up onto the boardwalks that line this area. Travel south, past the area's Fast Travel Crystal, and into the southwest region. Arlette is in a small cabin in the middle of the lake that dominates this area...
... and when you enter said cabin, you'll discover that she's been tending to none other than Raphael, who apparently survived the fall of Marylea. Sienna will explain the truth behind Raphael's 'beloved' Church, and he'll leave, disillusioned. The group will take Arlette back to Iden... only for her to run off again.
Fast Travel to the southern-most Fast Travel Crystal in the Kortara Mountain Range, then hop in your Sky Armor and fly east, to the southeastern area of Kortara. Land in the northern forest, then check in the northeast. You'll find Raphael and Arlette - just in time for an earthquake to swallow them both up.
Raphael will collapse after the third battle, but Arlette will ensure that he's saved. After some self-reflection Raphael will decide that he's not done with the world just yet, and he'll join the party.