A Pilgrimage for Power is a set of side quests where Coen tracks down Uriash glyphs on stone monuments and learns their shaman magic. Each part ends with a new spell manual, so they are a good way to grow your sorcery.
Glyphs are carved into stone monuments across the valley. Coen finds them and carves each glyph into his own flesh to learn its power. The Uriash call this magic skin signs.
Follow the windchimes to the monument, deal with whatever guards it, then inspect the glyph pillar to claim the manual. In Dark-Thing, a miniboss waits near the top and a pair of Uriash are camped beyond it. Talking to them calmly lets them leave without a fight.
Routes change with the time of day. At night, Shadowstep and Planeshift get you over walls. By day you often need to take a longer path and climb. Loot the area around the pillar before you leave.