I was thinking about wards, and I have come up with a variant of a ward against demons.
Circular Ward against creatures of the night
ReVi (Vi, Vi) 30
R:Touch, D:Ring, T:Circle
Creatures with might of 20 associated with the Infernal, Faerie or Magic realms cannot cross the ward.
Base +1 Touch, +2 Ring, +1 Circle, +2 requisites
As you can see, it uses Vi requisites to effect the different realms. The question is though - is this valid? I think it would be, and it would make everything a lot simpler. A Demon's Eternal Oblivion which would work on Faeries as well - it's just at a higher level than a custom one.
hm......im not sure about that, as all of the spells in RAW that deal with creatures/effects of the different realms have individual spells for each realm and basicly, your breaking that...the effect could be a good goal for original research tho
IMS I certainly would allow the effect - one additional magnitude per additional realm affected. It is not exactly an effect described in the RAW, but it doesn't seems to break any limit of magic, each single effect is vanilla hermetic magic, basically I think there is no rule saying that various effects can't be combined and the power level seems appropriate. But considering various older threads I know this attitude is not generally shared.
Not only is there no rule against it, but there are spells that follow exactly this procedure. However, it would just be ReVi, not ReVi(Vi,Vi), but I think you did that for clarity. As long as you have those two extra magnitudes, you're OK.
I think it should be allowed. I would go further, and premit one more magnetude to affect two realms, and 2 more magnetudes to affects ALL realms (for game balance purpose : 2 mag for 3 realms seems too much extra magnetudes for the real added effect)
There can be no requisite for form, when the requisite is of the same form; we need to simply add magnetudes.
The formulae - one Vim spell = one realm affected - always had a counter-intuitive feeling for me while in play.
I Imagine one of our players, his magus and a strange phenomena happening, then a Intellego Vim spell to detect magical effect, with a result of "there is nothing there". You try your other, exactly the same, the same monochrome spell, but associated with the infernal realm instead. Mothing. And then you can't detect the feary realm, for exemple, because you would need another formulaic spell for that - and you don't have it. You try a spont spell, bu fail short, the spell is not powerfull enough. What a crappy scene.
What is fun is when you kick out your spell and it works. Difference in the type of realms are more of technical questions.
Well, the spell breaks no limits, nor does it do anything particularly earthshattering. On the other hand, something which wards against both the Divine and the Infernal by their magical signatures seems a little odd. I tend to favour the interpretation (as implied by the Hermetic Spirit Magic guidelines) that Form wards protect across all Realms (ie. A ward against fire creatures protects against burning angels, demons and faeries alike) whilst those of Vim protect against a single Realm regardless of other Forms. That makes the other wards useful, for a start.
That said, it does break nothing except perhaps my sense of thematic boundaries, so I see no reason not to let it fly in your saga.