The virtue Mythic Blood includes a (minor) personality flaw "at no extra cost". While I take this to mean that you do not gain extra points to spend on virtues from it, it's not clear whether it counts against the total maximum of two personality flaws allowed to a character. Personally, I'd say it does, but I'd like to see what the consensus is, and perhaps propose that a clarification be entered in the errata.
It is "free": it does not give points for you to buy vitues.
Still, it is a personality flaw, so it should count as the maximum of 2 personality flaws allowed.
The problem with personality flaws is that if you havea lot of them you become acaricature, and you are difficult to roleplay well. If you can deal with that (either by having a superb actor as a PC or because ou do not care about caricatures) you can have as many as you want. remember that the V&F rules are only guidelines.
Correction, MIGHT become a caricature.
A well thought up concept can easily handle far more than 2.
And can certainly turn out to be very realistic characters even.
The rule should really be rewritten to say something like be CAREFUL about it rather than dont do it at all.
There is no maximum number of personality Flaws, just a suggested guideline. It says Should Not, which means you still can, but it ought to be well tought out. It says you cannot have more than one major personality flaw. So in this case there is a maximum.
I tend to allow any number of personality flaws, but only give the point value for the strongest legal combination of some of them (usually one major and one minor; faeries get more, I think, and grogs only get the one minor.)
This keeps people from making caricatures for the sake of power, without limiting people that have an interesting idea for a personality that fits multiple flaws.