A
genius loci is the 'spirit' or awareness of a place, depending on the circumstances, different places can have entirely different vibes or a feel to them than others. Depending on just how strong or potent a place is (and any associated ley lines) can determine what sort of awareness exists, and what capabilities the place extends to a wizard performing a
sanctum invocation at the site. I suspect that the ability intellectus is quite rare, based off comments by
.
In terms of characters performing a
sanctum invocation to gain a tie to a
genius loci, which works out mechanically to spending Refresh to gain a form of Sponsored Magic, I would likely treat many if not most of the major potential sites as strategic locations/resources, which would either be already controlled or contested by other members of the supernatural community.
For example, Stonehenge would be a classic example of a site reputed to have a set of very strong ley lines. Assuming that this is correct, given how long that people would have known of the potential power which could be tapped at the intersection of potent ley lines, most likely that one or more individuals or groups would have claimed (or at least attempted to) Stonehenge as a
sanctum, and gained access to the power of the
genius loci. Given the sort of power boost that could potentially be gained, I would expect that a strong caster (mortal or otherwise) would be required to forge the bond with the
genius loci and that kind of bond would make a caster even stronger. In other words, a big fish would become an even bigger fish, and they would have most likely already been too big for most players, at least initially.