The first thing to know is that a Muto specialist does not need to be always the same person. People come with an image and a background that can condition the direction of the social encounter. Do you need to appear to be an armored knight? Perhaps, you would like to appear unthreatening, like an old lady with a stick, rather than a military-aged male with a weapon?
There are several ways to accomplish this. Simpler ways, like illusions, come with the drawback of being easily thwarted by faerie sight and second sight. Muto specialists probably have spells like Disguise of the Transformed Image (MuIm 15) or Image Phantom (MuIm20) to change appearance. “Like” is the critical word, as these spells are too limited by the size of the target. The common need to transform the image of a bigger person (+1 or bigger) or an animal like a horse (size +2 or +3) has made this version more popular between Muto specialists than the more widely known versions:
But for the Muto specialist, there are stronger options open. This spell is designed to completely alter the appearance of the caster, allowing to acquire any human appearance, including different garments and equipment’s (weapons or tools). Requisites are nuts, but that is no obstacle for the true Muto specialist, as the requisites are on the side of the Form:
So, the mutable identity of the Muto specialist aside, let's continue with what can be done to influence the outcome of a social encounter. Can be argued that Muto specialists are subtler than other specialist and some degree of social skill probably will be always necessary. But the Muto specialist can enhance its own ability using spells like Aura of Ennobled Presence (MuIm10). Of course, you don’t always want to be seen as an authoritative figure, so there are a lot of possible variations like the one that a friendly Merinita in my campaign devised:
Anyway, the Muto specialist usually works with what already exits, taking one emotion and transforming it into another. The level 3 guideline “Make a major change to a person’s emotion” can be used to gain a social advantage. Some ideas could be to change an emotion to the opposing one or to change the receptor of an emotion. For example, you could receive the same emotions that the target has towards his father or mother. The problem with this is that the Muto specialist is not always an Intellego adept as well, so knowing details of the life of the target could be tricky. No use on getting the emotions that he has towards his father if he hates his father.
But sometimes you could have some secure bets about what the target is going to feel. An extreme example would be this spell designed to circumvent the drawbacks of the Gift, albeit in a limited way.
But sometimes you need big guns. Like an instant shared past with your interloper. I have developed this:
This spell was designed taking into account the limit not to generate warping, so multiple casting would be possible, thought normal rules for continuous effects apply.
However, this other similar spell from Guardians of the Forest (pp 72) seems to be Creo with requisite Muto:
Not sure of what I have done wrong with mine, though. If somebody can correct me…
If everything else fails, you can always use Show of the Flames and Smoke (MuIg10) in the nearest fire and disappear. Another way of quickly ending a conversation gone wrong in the second or subsequent floors of a building is to apply Mind of the Beast MuMe(An) 30 to change the mind of the subject to that of a prey bird (like a dove). Any violent motion from the part of the caster is likely to make the interloper rush to jump by the nearest window. Of course, that cannot possibly be considered a social encounter, can it?
That's all. Feel free to answer with your own troupe devised solutions, critiques, suggestions or even create another thread with your favorite specialist/problem combination.