I don't believe there's a baseline in CrVi or similar that allows you to magically "mark" a target, I was hoping to recruit people's thoughts on the impact of creating a baseline for it.
The situation that I'm in is that I'm creating a kind of eye-spy enchanted device, with one power, a touched target gains a superficial mark (the darkening of an iris) but this marks the target as an arcane connection to a second ability of the device; Which is that the bearer of the eye-spy device can use it to cast an arcane-connection range spell to marked targets.
I realize that I could be taking hair samples, particularly since the first power is touch-range anyway, but that doesn't quite satisfy the romance of similar effects.
A simple way to do this is have two things, one of which becomes the arcane mark and one which is a connection to it. Don't use magic to create the mark, instead use magic to take something that you've already got one or more ACs to and mark your target with it.
Here's how I'd do it:
- Get the AC
- Use a spell of range sight and duration sun to turn the thing you've got an AC for in your hand into an arcane mark tattooed on the target's spine (spine, so they're less likely to see it before step 3)
- Since you're a Merinita magus use a day of rekoning (Duration Sun arcane tunnel) spell to cast a spell on your AC to turn it into a tatoo for duration until. That way it can't be dispelled easily.
- you have a vial of tattoo ink.
- You remove part of it and fix as a permanent AC to the rest.
- You use Rego Aquam to inject the rest of the ink it beneath the skin of your target to form the shape of your awesome arcane symbol.
I'm less fond of actually making an AC with magic, that's what synthemata and true names are about. I wouldn't want to superceed that with standard hermetic magic.
I believe in the latter of Erik's examples, the connection would still be to the tattoo ink. In some cases this is not especially consequential - if you wish to throw a Pilum through an Arcane Connection then throwing it at the ink on their back is tantamount to throwing it at them. However, intellgo spells would have requisites (to see the body as well as the water, while scrying, for example), and other would be impossible (MuCo spells trying to target the person tattooed, for example.)
Unless, of course, your troupe feels the tattoo becomes a part of the person tattooed? It's a bit of a grey area, I'll admit.
Well, you can magically mark a target with core book CrVi, but that doesn't make the AC you want.
There is one guideline that nearly does: RoP:tI p.121 lets you do it for a demon. But there are a few guidelines there specifically toward demons, and in some cases this appears to be a temptation to me, and in such cases it's probably meant to be limited to demons. I would guess this one should be limited to demons as it specifies demons.
But why bother? Why not just use ReVi? The item creates an intangible tunnel to the touched target. You could use D: Moon with unlimited uses at R: Touch. That lets you start it in the first place, and you can keep renewing it as needed. You could include ReVi to temporarily close the tunnel and PeVi to permanently end it or the temporary closure early. If it's made with experimentation, there could be a side effect that colors the eye of someone with an intangible tunnel from the device to them.