Foci (foe-kai)

The Foci are naturally occurring clumps in the magical Weave. Foci that the Anteceans found and harnessed are marked by Antecean ruins that used to be housing facilities: stone rings and arches carved with magical sigils housed in structures of varying degrees of complexity and artistry. It was once believed that Antecea created the Foci themselves with these facilities, but the discovery of "free-standing" Foci with no ruins to be found has largely dispelled this idea. 
They are by their nature quite volatile and often unstable, and tampering with them in an uncontrolled manner often results in wild magic surges. Despite this clear danger, adventurous sorts often find themselves unable to resist poking them for whatever reason.

Manifestation

The Foci themselves appear as twirling vortexes of distorted air currents that shimmer at the corners of vision. On occasion, the Foci is imbued within a piece of nature, like a tree, pond, or boulder. Rarer still are those that have become intertwined with manmade structures. An object infused with a Foci almost always bears a supernatural mark, be it an otherworldly coloration, unnaturally large or overgrown appendages, or an apparent immunity to weathering and the passage of time. 
They will also share certain aspects with the plane or planes they are most strongly connected with. For example. a Foci connected to the Plane of Fire may emit a cloud of smoke and embers from time to time, or a Foci with a strong link to the Abyss will stink of rot and decay and chill the air around it.
If there magic is agitated or amplified, their physical presence becomes more opaque and distorted. They also become more liable to send off flares of potent magical energy when put in this state. Infused Foci seem to generally be more resistant to tampering but will also distort and charge the air around them if overloaded enough.

Localization

Foci pop up seemingly at random; scattered across the lands. They tend to be in more wild areas, but only because smart civilizations keep their distance from them when choosing where to settle. Even the Antecean's built large population centers at a distance and only kept minor outposts around the Foci they harnessed and studied.

Type

Metaphysical, Arcane