I've been mulling over mythic blood recently. I really like this virtue, thematically at least. However, I'm under whelmed with its power and I suspect this is due to a lack of creativity on my part when it comes to the ability granted.
I'm going to ignore the free minor magical focus as it comes with a free flaw of equal value and so kinda cancels itself out.
So really, Mythic blood has two abilities, no lose of fatigue when casting formulaic spells and failing by less than 10 points, a happenstance than in my games has probably happened no more than a handful of times. And that ability.
Now the ability is spell like, as fast as a fast cast formulaic spells and has a maximum level of 30, reduced by five each if you want it silent or still. Penetration needs to come out of that 30 too.
My first thoughts to make this ability make the virtue worth it are thus
it should be something you'll want to cast often, you pretty much paid a major virtue for it.
it should be something you cast on others. The requirement for penetration to come out of the 30 spell levels makes anything that might penetrate virtually useless
It must be something that will maintain usefulness as your power increases as neither it, nor its penetration can be increased later.
there is no roll and hence no possibility to botch, this makes it useful for casting in hostile auras
My initial thoughts were vim effects. Muto vim would allow for a wizards boost that maybe matches the minor magical virtue, A level 30 wizards boost could boost appropriate level 25 spells and could be very useful if you intend to spam i frequently (a good concentration score is essential of course). A minor focus in creating fire matched to an ignem wizards boost could be pretty nasty.
An intellego vim spell would allow you to see all active magical effects (like sight of the active magics but without the technique/form data).
Dispelling effects are a little more specialised and so its of limited use here.
Has anyone else used this virtue to good effect or does anyone have some good ideas for creating useful abilities?
I've also been thinking about Mythic Blood recently. This was partially sparked by The Best and Worst Virtues thread, but also by the process of statting out a Verditius wand-maker, for whom I had not found a suitable Major Virtue.
Some additional effects that may be well-suited to the power:
Imaginem effects: the first that comes to mind is invisibility for the character himself, but it could also apply to someone else. Creating illousions would also be great, as they don't need to penetrate in order to be effective. A broad MuIm that can adjust the caster's image so as to provide a variety of bonuses for social interactions (based on Aura of Rightful Authority and its variant from HoH:S) is also an interesting possibility. Something similar to the ReIm 30 Image from the Wizard Torn could also be of some interest.
A ReAn effect might make the character a very good animal trainer/controller (see Commanding the Harnessed Beast, for example).
Flying effects would be possible, either through ReAu or ReCo.
In general, Intellego effects can be quite useful. You mentioned Vim, but others can be useful as well. Animal would allow him to speak to any beast, Herbam to speak to trees and plants. Corpus/Mentem to speak to the dead. Terram allows for a super-dowsing skill.
A MuCo effect can make you into a shapeshifter.
Teleportation effect though ReCo (whether you need requisites would depend on your saga).
For the combat-oriented character, a damage effect in a variety of Forms is an option. It might not be worth much against higher-powered supernatural creatures, but as you could fast cast it without fatigue, it can be used to handle weaker creatures as well as mundane ones.
I don't consider MB to be that great a virtue. It does have niche uses, yet has neither the power nor synergy nor even flavor I'd want from a Major Virtue, Hermetic no less.
It includes a minor focus, but that can be taken without losing the MHV slot. It includes a minor personality flaw. It includes 30 levels of effect without Penetration, which is most interesting for a starting character and/or for effects that would normally require many requisites (such as teleporting yourself and everything you wear, from the gold in your pocket to your cheese sandwich, lit lantern and full water flask) and/or for effects that risk many botch dice but rapidly becomes less relevant. I don't think it is very good for a shapeshifter because, like any other constant Muto effect, it warps.
Finally, successful casting of formulaic spells do not cause fatigue. If this were a minor virtue, many characters would still not bother, so I'd call it a solid minor virtue.
So we have 1 excellent minor, 1 good minor and 1 poor minor virtue plus a minor flaw. Not great economy.
I like the idea of the virtue, yet it doesn't capture the idea of a Hermetic lineage well imo. Why are they all good at non-fatiguing formulaics? That's not what I expect from a Diedne or Verditius... (So why do I like SFB? After all, not all faeries should be able to see in the dark. Because this ability is a very small part of what SFB does, so I ignore it. Most of SFB has fantastic flavor, power and synergy.)
The fatigue ability is probably best for a generalist. (The TeFo specialist has so much left over for Penetration that he is not likely to fatigue in adverse circumstances, though the spell is more likely to bounce.) But as a generalist, I'd rather have FM or FFM or LLSM...
My favorite way to have "Mythic Blood" is to just take the virtues that make sense to me, and ascribe some of them to a lineage.
That's reasonable. Sort of the way I would not (except in a Cthulhu crossover) give someone Warping Points for botching a Second Sight roll... "You happen to be looking at the tree and you see... please roll a die.... 6 botch dice for the Aura.... oh my god! Twilight!..."
Personally, I like Mythic Blood for that one spell I'd really like from a school combo I'm otherwise not going to get much higher than the "able to train apprentices with" level of 5. This will usually be a Personal effect or something you otherwise don't need to Penetrate for. For examples, think of a character who doesn't care about Rego or Muto at all. Well, shucks, that makes travel a little difficult. No worries, Mythic Blood's got you covered. Sun duration version of The Gentle Beast... Cloak of Black Feathers... The Seven-League Stride... All level 30 effects that help you get your Gifted rear end around. The idea is the same for other applications.
... Not that such a usage really does the flavor of the Virtue much justice unless you're specifically wanting to play a "I refuse to embrace my heritage!" character, given that in most actual cases simply for common sense's sake, you probably won't have an ability completely unrelated to your focus as a Magus. But it's the most useful way to use the Virtue, at any rate.
I would recommend going with something useful but that doesn't match up well with your Arts. Maybe you have a Minor or Major Magical Deficiency but there is one effect from within that area that would be really fitting.
Personally, I would allow constant effects, too, and without Warping as Mark said. This could allow non-dispellable breathing of water or something similarly, conditionally really useful.
Also, there is a small additional side bonus to Mythic Blood: you can take Heroic V&F. It's still not one of the stronger ones, but this does open up a few possibilities.
