This page of the guide to AC Valhalla Dawn of Ragnarok contains the location of all the abilities available in the Svaladal region.
Location: This ability is hidden in a small building located in the northern part of the region.
Before attempting to collect this ability, it is best to complete the raid beforehand. This way, no one around you will disturb you.
This task is fortunately pretty easy. All you have to do is grab the beam and direct it at the scattering element. It is located to the right of the entrance, between walls.
Then go out to the staircase and run all the way down. You will see a wall covered in ice on the right. Destroy it and enter the room. You will easily find the book with the new ability.
The first thing you must do is enter the building. You can easily do this by climbing up to the balcony and through it to the inside. Once in place, grab the item and aim the light beam at the point above the door.
Go into a small room and remove the orb from there. Insert it into the empty projector so that you can direct another beam of light.
Eventually, direct the beam so that it perfectly hits a point outside the building. This will open the door to the room with the book.
Location: Sol-ok-Mant Vault
In order to even begin solving the puzzle that leads you to the book, you must use the power of Muselheim. When you activate it, you will be immune to lava.
Only after doing this can you move the ray so that it reflects off a point on the opposite wall. Then shoot it down so that the light is pointing to the right. This will open the passage.
Continuing down the lava you will run into a cave where you the skill book is located. Right next to it lies a diagram that's worth picking up right away.