Regarding the covenant's aura, the statue, and a vis source for the covenant...
The Temple
When the site of the old temple was discovered, it looked like this.
Within the forest south of Koblenz, some distance from the Roman road that links Koblenz to Trier (about 80 miles southwest as the bird flies), is a clearing in the trees. That clearing forms an oval 80 paces by 115 paces (widest on the southeast-northwest axis) where a crumbling wall stood. At the north-northwest tip of the wall once stood a large gate building granting access to the temple grounds, but three smaller gates also pierced the wall on the northeastern side.
Inside of the walls, small trees and bushes have established themselves well and clutter the space, initially hiding the ruins of the temple itself. But as one travels from the main gate towards the center of the walls, soon the temple loons through the trees. It still stands, a bit closer to the gate than the center of the oval formed by the walls.
Although the temple was obvisouly torched at some point and is mostly collapsed, it did not burn completely and the remains of the building are still impressive. A columned hall 20 paces wide by 21 paces long surrounded the 9 by 10 paces Celia (holy room). Inside of the Celia are two large statues of Mercury and Rosmerta, still holding hands. Rosmerta's right arm has broken off at the shoulder, and both statues are scarred by the centuries of neglect. Their surface is scored and shows many cracks, but anyone approaching them can still feel a shiver of raw power emanating from the stone. A small stone altar stands before the statues.
The Aura
Within the Celia there is a magical aura of 4, but quickly becomes weaker as one moves away from the Celia. The whole area within the old walls has a magical aura of 2. This was not always the case, however, since the aura comes from the statues the aura was weaker initially. Cleaning the rubble and rebuilding the temple helped, but restoring some of Mercury's worship helped even more. If the rituals cease, however, the aura will weaken again (Flickering Aura covenant hook). This was revealed when the site was initially investigated by the magi.
Space for the Labs
The area of the Celia is approximately 850 square feet, so a +2 Size lab can be establishe there. The Celia could even be expanded slightly so as to allow a +3 Size lab and still benefit from the stronger magical aura.
Other labs can also be established anywhere inside of the walls. A probable way to do this would be to build a large villa-type building around the temple, where the magi can have their sancta and living quarters, with restricted access to the courtyard inside the villa. This would add a degree of protection to the Celia and the valuable statues. Living quarters for the covenfolk and grogs could then be set up either in wings of the villa or in seperate buildings within the wall enclosure.
Mercuralia and Altar rituals
Once a year, on May 15th, the rituals of the festival of Mercuralia must be observed or the aura is reduced by 1 within the walls, and by 2 within thin the Celia. The ritual is fairly simple.
Throughout the year, a small flame must be kept lit before the statues, with fragrant woods being fed to it regularly. A silver bowl of water must also be kept full before them. Once a year, during the festival of Mercuralia (May 15th), the water must be ritually sprinkled on the head of all those live inside the walls, and over each door lintel within the walls as well. This needs not be done by a single person, but the sprinkling must be done using a fresh laurel branch. The difficulty lies in the fact that laurel trees do not grow in the Rhine tribunal, so a branch must be imported each year from the Mediteranean region and kept fresh.
If the ritual flame dies, the aura inside of the Celia immediately falls by 1 and a more elaborate ritual must be performed to restore it (this takes a whole week). If the Mercuralia ritual is not performed, the whole aura (inside the walls and inside the Celia) fall by 1 as well for the next year (until the next Mercuralia). So the aura within the wall can be 1 (without Mercuralia ritual) or 2 (with the Mercuralia ritual), while the aura within the Celia can be 2 (no rituals), 3 (either the altar is maintained or the Mercuralia ritual was performed) or 4 (with both the altar maintained and the Mercuralia ritual).
Vis Source
As the water is sprinkled throughout the covenant site on Mercuralia, the wood and leaves of the laurel branch slowly gain a silvery hue. Once the ritual is complete, the branch contains Vim vis. The raw vis dissipates as the branch dries out and looses its leaves, but may be collected into a different receptacle.
). If someone spends the season to make it a minor (or major) feature, then other magi could also do so without spending more than for a free virtue/flaw (a few days). After this we could very well have a few labs not using it (or still using it as a coat rack), one using it as a minor feature, one as a major feature and maybe some as a minor or major focus (cheaper in space-cost). It would all depend on how each fits his work to the lab.
