From PathfinderWiki

The Three
Areas of Concern
Lie, share your divinations without payment
Cleric Alignments (1E)
Domains (1E)
Knowledge, Law, Luck, Rune
Subdomains (1E)
Curse, Fate, Thought, Wards
Cleric Alignments (2E)
Domains (2E)
Fate, glyph, knowledge, truth
Favored Weapon
Green three-pointed knot
Sacred Animal
Multi-headed animals
Sacred Colors
Blue, green
Source: The First World, Realm of the Fey, pg(s). 28 (1E)
Gods & Magic, pg(s). 79, 126–127 (2E)

Magdh is one of the Eldest, a divine fey creature of tremendous power said to be able to reshape the very fabric of the First World on a whim. Magdh is a feminine demigod with three faces and takes the role of prophetess and seer amongst the Eldest; her skills of prophecy and in understanding fate seem to be great. She watches chains of events from origin and culmination and the tangled lines that form the ultimate fates of everything, and no one knows exactly about her goals or motivations.123


Magdh resembles a robed human woman with three equidistant faces (one red-haired, one black-haired, one blonde) on her head. These faces can effortlessly rotate to address the same person, sometimes mid-sentence. Each face appears to represent a different aspect of Magdh's personality, but not the same one. When necessary, she can split into three women, but often becomes less lucid or more reserved for a time after doing so.3


Magdh's personal residence is the Forest Pools, a series of ponds of different sizes spread on an open glen in the Weeping Wood, next to the Evergrove. She spends most of her time reading events on and gleaning opaque visions from the pools. Magdh will accept visitors who wish to partake of her future vision; such searchers find a welcome both strange and mysterious. No one knows the criteria for a pilgrim to be allowed a glimpse of her knowledge, or the toll she demands for such a glimpse, which can be anything from trivial to impossible.314


Magdh has few retainers, and has an affinity with norns (rumour has it that she might have been three norns who bound themselves together), and allows them to assist her divinations. The only other inhabitants of her realm are multi-headed faerie dragons, who often torment travellers (in a non-malicious way), but always follow her orders without question. Magdh often sends her minions on quests that seem to make no sense, and accompanies them in especially important ones.3


Due to the belief that Magdh is single-handedly protecting the First World from some calamity, the other Eldest and many other creatures do not interfere with her or her quests. Sometimes, they might ask for interpretations of her visions, as she is said to have seen the end of all things, including the Eldest themselves. Shyka is the Eldest closest to Magdh due to their shared time and fate portfolio, but they intensely disagree on some fine details.3 Magdh often cordially debates with Magrim over runes.5


For additional as-yet unincorporated sources about this subject, see the Meta page.