In God of war Ragnarok, Casualty of War: The Scroll is one of three Favor side quests in The Plains region of The Crater, whereby you have to talk to a ghost and then find something for them. The Crater is a hidden region of Vanaheim that you can discover by completing the Creatures of Prophecy goal on The Path main story quest line, then completing the Scent of Survival side quest Favor by following Helka out of Freyr’s Camp.
How to start Casualty of War: The Scroll
Starting from the Crater Entrance Mystic Gateway, go over the wall to the north, then drop down and head left. Drop down, then head left along the side of the canyon, then swing across and go back up the other side. From the large pond, head northwest, then drop down and swing into the cave.
There’s a chest here covered in vines that you can’t remove just yet, so swing to the southeast, then turn right and enter the dark cave. Fight your way to the end of this cave to find the ghost of Runa (and the vine “mother” you need to destroy to get to that chest). Talk to Runa, and she will ask you to find half of a scroll.
Where to find the Scroll
Travel to Western Plains Mystic Gateway (if you haven’t discovered it yet, then you’ll need to play through the For Vanaheim! quest to reach it). Look down over the ledge next to the Mystic Gateway and throw a Draupnir Spear at the glowing air current below (it should turn red).
Don’t detonate it yet. Instead, drop down off the east side of this platform and turn to the left. You’ll see two more flowing air currents side-by-side on some rocks. Throw a spear at each of these, then detonate all three spears (press Triangle) to clear the rocks out of the way. Go through the gap and the Scroll is straight ahead.