From LSWiki

Class: Affinity Skills
Attribute: Willpower
Pedagogy: Spirit Alteration
Practitioner Term: Goetic Investee
Hidden Skill

This skill represents an infusion of goetia, also known as theophanic energy -- the power of divine influence in mortal affairs --
into one's essence, making one resistant to the influence of goetic forces, potentially even to the point where exposure that would
have been harmful is instead restorative.  A modicum of resistance to oneiric energy, the stuff of dreams, is also conferred. 
However, the greater an affinity for these energies one develops, the more vulnerable one becomes to both raw spiritual energy and
abstract magickal energy.

Goetic investiture can be increased by exposure to theophany or dream, as well as degraded by exposure to ectoplasm or magick,
changing more quickly according to one's astral perception.

See Also: goetia resistance, magick affinity

Trainers

Guild:
Traveler temple : Amon Tyrice 
Temple of Aeda : Phyrra