Ranulf from MoH now 150 years post apprentice!!!!

[Tellus]

@Erik Tyrrell

So can a muto vim spell that dynamically alters another spell be supported by a version of "Maintain the Demanding Spell"? It doesn't run afoul of any printed rule that I'm aware of but it does cut very close to the restriction against enchanted devices being able to cast muto vim.

Not having checked the relevant effect in a while:
You're just using ReVi to maintain a D: Conc spell, right? No problem in that (assuming it was originally made with the right guideline, I have no recollection about seeing it before, but it's early here, so yeah).
No restrictions on ReVi for devices that I know of.

Also, if I wizard's boost a ritual do I need to supply more vis?

As far as can tell, yes

Here's a relevant quote from the errata for folks who may have not seen it or forgotten. My spell doesn't make much sense if you haven't read it.

Muto Vim Guidelines (p. 159): Replace the final paragraph with the following: "Muto Vim spells work by altering the magical energies that create the spell as it is being cast. The spell is the result of the combination of the base casting and the Muto Vim effect, and has its effect once both the casting and the Muto Vim effect have finished. This means that a Muto Vim spell must have a duration at least as long as the casting of the target spell, but need not last for as long as the spell itself. For normally-cast formulaic spells, a Momentary Duration is sufficient, but if the casting time is longer for any reason, the Muto Vim spell must also have a longer Duration; Sun is sufficient for any practical Ritual."

My favorite here is a trick based on the Neo-Mercurians (TMRE), who practice performance magic based on their rituals. Beautiful solution I thought.

You should note though, that MuVi on the Aegis has caused controversy before:
https://forum.atlas-games.com/t/e-mail-verification/172/1] and spin-off here:
[url]https://forum.atlas-games.com/t/spun-off-thread-is-the-aegis-of-the-hearth-hermetic/7589/1].
I suspect that discussion is what caused the note on Wizard's Boost in the [url=http://www.atlas-games.com/arm5/arm5errata.php]errata