It takes a lot of XP to get most of them to max level, and even having beaten the game, I still have only maxed a scarce handful. You will find them all at level 1, and all can be upgraded to level 3. While obviously you’re going to use XP from combat and missions to upgrade your various skill trees, you might forget that you also need to use XP to upgrade “rune” abilities, ones that attach to your axe and Atreus’ bow that are special moves. Don't Forget to Use XP To Upgrade Axe Specials
