For a moment, let's pretend that, for some reason that a group of powerful magi (we call them the conspirationnists as to NOT refer to them as Diedne survivor, because that is not so obvious) have the desire to enslave most other magi they encounter, and turn them into tools for their grand plan. Their mean tool will be something between magical creature, animated magical item, dark faerie and golem, that is called the Shrike. Independant from them, but sharing their goal, he would have been working for centuries, in the shadows. (Maybe he has even started by enslaving them... because you know, Skynet style.)
They (have) develop(ed) powerful items for it:
1° multiple ReMe "enslave" type item with a permanent duration, each of them will be used on ONE particular magus prisoner. This item doesn't penetration since it will be used when the parma magica is down. I'm considering adding a bit of penetration (hitting the +20 for +40 penetration) just to cover the familiar innate might (which would still be active at sunset/sunrise on the magus) and Form mentem. This item allows the Shrike, to control all his "slaves" into doing what he wants... that is mostly : "make me another item"; "Redo that item X that some members of the Order have broken during our last confrontation"; "extract vis for your other enslaved colleaga's", etc.
2° the slaves being prisoners in a remote, inaccessible locations (under the earth, in a cavern which no one know that it exist) where they are teleported by our Shrike at the time he enslaves them. There, there are a lot of laboratories located in a underground inversed tower (think calebais-like). In the central empty column , there is a gigantic (magically floating) diamond, which is a fixed arcane connection to our Shrike. It is the heart of the system. Most of his magical best defenses are not weared by the Shrike, but use that Diamond as AC so that in case of combat, those items can't be destroyed even if the Shrike is put in bad shape.
When the magi do what they asked (see 1°) they create mostly items. Some will just use AC range, with the diamond, other such as offensive items to be used on the foes of the Shrike will have to be "given" to the Shrike. For that, they can teleport such new item if it has to be used by it : a wand of fire per example would be useless at arcane, but using a teleportation spell with the fixed AC, the enslaved magus can have his creation teleported to the Shrike.
Since the Shrike enslave all magi present there, he can use magus B (teleport expert) to gather items made by magi X and Y who are not able to teleport their creation to him.
Let's pretend vis is not a issue: the Shrike having a power to teleport vis he finds (on his enemies' bodies or in the wild) to the diamond, where his enslaved magi can just take it.
I face with 3 issues:
3° those magi need to eat
That's a big problem.
First, if any magical eating with a permanent duration item could be used at the price of unravelling the effect of magical eating in case the item is broken, is possible, i certainly would go that way, because that would make a remarkable dilemn: PCs couldn't be able to "kill" the Shrike, because doing so would destroy the feeding-item, which will kill all the prisoners of the Shrike.
But that brings us to the digestive issue.
I know that magic can't create food from nothing: like all creation from nothing, it requires Vis, or duration.
- Vis means ritual, meaning not possible by item (unless one of the enslaved prisonner could do that - folk witch or mystery - but that would require more ressources (integration with folk witch, spirit to sustain ritual item? for mystery [i'm no more sure about that mystery thing]).
- duration means that during the duration "food is real". But obviously that brings two issues:
i. reccurence of creation of food: one item creating food A with duration X can, with multiple uses, create food B with duration X. If uses are infinite, that can create a lot of food. Correct? But all this food lasts only for duration.
ii. from which point is the eaten food "transformed" and its disappearance no more an hindrance? after 1 day? 10 days? 30 days? (two first possibilites allow the use of moon. Last is too long and problematic).
Second, if item is not possible, I guess a "enslaving workers" would be good too. (Or maybe better, use one of the enslaved magus to control the flock of grogs so that they do food. That reduces the number of items required: only magi are thus controlled by the Shrike, and one magus is in charge of the grog controlling.) In that way, maybe have that magus, or another, be in charge of vis casting food could work too.
Anyway, before that system could be put in place, a temporary solution would be needed anyway...
4° they need to have material
Obviously teleportation of item encountred by the Shrike would work, but that would be time consuming and he has an Order to eradicate.
He could ask some enslaved magi to create the gathering items, but those magi would need prior material.
Again, ritual magic to create lab content is a possibility, but there is the first step: how to let one magus develop that ritual if he has not material.
Obvisouly the laboratories in their prison will be set up by the conspirationists, so maybe I can use the "initial" package. How long would last an un-maintened with ingredients lab? does Covenants have an answer? i don't remind it.
5° do they need to sleep?
Enslaved, they can work, but I guess at some point their bodies will just go out of energy and they will fall asleep. Since the enslaving power is permanent, it is not a problem, but could the enslaving power remove the need for sleep, at the price of some advanced aging process? do you have any clue on this matter?
Thank you for your ideas!