Lunars and Larceny
The Changing Moons are referred to as highly skilled disguise artists and thieves, and oh boy are they. Here, I'll go into how the Lunars excel or don't excel at the different aspects of Larceny.
When it comes to disguise, the Lunars, especially the Changing Moons, rank up with the Sidereals as masters of hiding their own identity and setting up fronts. While the Sidereals have the Arcane Fate and Resplendent Destinies granting them that capability (one should note that they don't have any Charms for it, though), the Lunars have shapeshifting (note that shapeshifting to a Lunar is like astrology to a Sidereal-- if you're serious about being effective as one, you need to familiarize yourself with the uses of their niche power), Charms, and an anima power.
First, the Changing Moon anima. Don't read it in terms of what it can't do, read it in terms of what it does do. Specifically, it's an automatic success on a visual diguise roll. As far as looks go, it grants you a perfect disguise. Note the lack of restrictions on the form you have to be in to imitate someone else-- while you should stay within the bounds of logic, there's not much to prevent you from using the power as a dog to imitate another dog, or using it as a beastman to look like a tall human you're familiar with. The power doesn't cover vocalization or touch, but neither do mundane disguises. Again, Lunars get magic powers best supplemented with actual prowess-- if you're a Changing Moon, the Manipulation + Performance (or whatever your ST prefers) roll to imitate voices shouldn't be that hard if you've built your character with that in mind.
Second, general shapeshifting. While the generic shapeshifting power won't help you imitate people or sneak into places as a non-descript human, it's certainly useful for hiding your own identity to turn into an inoffensive animal (preferably not one of your true shapes, for Tell purposes) and do what inoffensive animals do. Even the Wyld Hunt will be hard-pressed to track a street dog in Nexus.
Third, Charms. Hide of the Cunning Hunter is a basic prerequisite if you're looking to hide your identity if you're a casted Lunar-- if you want to expand the options for trickster Lunars in your game, allow Lunar PCs to have that Charm for free instead of Finding the Spirit's Shape, although that's obviously not canon.
That said, Shaping the Ideal Form is a godsend-- it lets you change the appearance of your shapes, including your human one. Other than for aesthetic purposes, this is an excellent disguise power, like shapeshifting, for disguising your identity. It is very useful for keeping people from recognizing you from meeting to meeting (sound like the in-game usefulness of the Arcane Fate to anyone), and is also the only way to modify your human shape without considerable extra focus. It also enhances the use of general shapeshifting for hiding your nature-- the Wyld Hunt will be even harder-pressed to track a street dog in Nexus if it keeps changing physical description from being big and brown one minute and half the size and black with white spots the next. The Charm is only 2nd tier, and comes after a Charm that you get free with your tattoes if you play a casted Lunar. If you've got an extra slot for it, get it.
Many-Faced Moon Transformation extends the utility of Shaping the Ideal Form and is also useful if you intend on any breeding projects like producing beastmen, but other than that is mostly a speedbump-- if you want to shorten the Lunar trees, merge it into Shaping the Ideal Form. Prey Skin's Disguise, once you've gotten OK with killing mortals and drinking some of their blood (not for the squeamish, but not morally all that different from the mass slaughter of the opposing army of the month you see in a lot of Solar games), is of course like the Changing Moon anima but without the restrictions on voice and touch. Brush up on whatever skills your ST says are neccessary for doing imitations, but the difficulty to spot you should be quite high since you, physically speaking, are the person you're imitating.
For tons of fun, use all of these powers in conjunction. It's really a lot of fun when the great duellist Dispara is revealed to be the Imperial Satrap (who you ate) in magical disguise, who is revealed to be a shapechanging monster when she turns in a marauding hybroc who eats a few cows and flies off into the sunset. It's even more fun when the resulting scandal leads to the disgrace of no fewer than 20 Dynasts back on the Blessed Isle. This is part of why the Changing Moons are called dangerous tricksters.
A note on Deadly Beastman Transformation and your Tell
The Sidereals have Paradox to discourage them from screwing around with their identity in an inconsistent manner. The Lunars have their Tell to discourage them from being seen in their true shapes all the time if they want to hide their identity, especially if their identity involves "9-foot tall killing machine".
Remember that if you're not playing a character who likes to disguise himself as something he's not (you know, like a normal mortal), then having a very prominent Tell is not a problem for you. Beat up or social-fu anyone who questions you for having very large sharp teeth, and run like crazy when the Wyld Hunt shows up. Believe me, it's more fun than it's cracked up to be. Buy as much DBT as you please, and go wild. Note that a lot of games at the edges of Creation, dealing with the barbarians and the Wyld, work quite fine for this.
If you're not that worried about disguising yourself as others, but would like to be able to move about without everyone instantly knowing you're a supernatural, limit your DBT purchases to 2 and stay out of your true forms when you can avoid it-- most mortals won't be able to get the 5 successes needed to spot you out of true forms, but they will occasionally score the 3 successes needed to spot you in your true forms. This means, if you want to move among civilized human populations as a civilized human without the occasionally lucky perceptive guard noticing your tail, you'll need either Masking the Brilliant Form or Prey's Skin Disguise-- the latter is nice if you already have it, but otherwise I suggest MtBF for safety's sake, especially if the people who you're trying to fool are a physical danger to you.
If you intend to do a ton of masquerading as other things and people and don't wanna invest in Masking the Brilliant Form, don't buy any DBT. If you intend on rubbing shoulders with gods and Exalted and none of them having the slightest chance at all of noticing you for what you are, ever, then don't buy any DBT and buy MtBF, to make your Tell near-impossible to spot without major magic.
Note that if you intend to use your ultimate disguising ability to ambush and backstab and assassinate others, either a level or two of DBT, or a few well-chosen combat Charms (be they traditional, like Deadly Claw Blow, or non-traditional, like Moonsilver Monkey Excercise), or an animal form that lends itself to that sort of thing (giant boa constrictor?), or some mix of all of the above is recommended.
First question a Lunar thief always should ask is "can a cat, ferret, bird, or monkey get to it?". If the answer is yes, shapechanging alone will suffice for the job. Remember that if you grab something as a human and shapeshift, it goes Elsewhere until you shift back to human.
Second question is "can a mouse get to it?". If the answer is yes, Humble Mouse Shape it is.
Third question is "is where its at totally airtight?". If the answer is no, Rat Head Technique is your friend-- you can fit a human shape through knotholes, so you can totally fit a monkey shape through keyholes and (if you've got Humble Mouse Shape) a mouse shape through most any hole of a size larger than "molecular".
Fourth question is "do I need tools?". If the answer is yes, Tool-Hand Technique is very nice. Not only is it a full toolkit you don't need to buy or carry around (that adds 2 dice to Craft checks), but you can use it in any shape, just in case the space is only big enough for a ferret but you still need to pick a lock or work with tiny bits of machinery.
Now, remember that you're a Lunar, not a Solar. You're actually gonna need some Larceny if you want to pick locks and stop traps, even if you can turn your fingers into lockpicks. You're actually gonna need some Stealth if you want to go about unnoticed, even if you're going about unnoticed as a mouse. Use your abilities in conjunction with your magic. And if all else fails, well, turning into a bear and whipping out Door-Breaking Method works wonders, but be ready to flee when you have to.
Navigating Criminal Underworlds
Use your Larceny ability.
Sorry, this is an aspect of Larceny where you don't have any helpful magic and will have to use your normal skills.
That is, if you ignore that a being of your criminal skills (if you've invested in either disguise or thievery or both, see the sections above) and shapeshifting prowess not only should be able to get whatever information he needs on the local criminal underworld if he puts his mind to it, but should also be in high demand from anyone who could make use of your unique talents.
Solars make excellent disguise artists, thieves, and mob bosses and have magic for all three (I'm looking at you, Inescapable Shadow of the Sun). Sidereals are excellent disguise artists and mob bosses, but need to use their actual Larceny ability for technical thievery. Lunars are excellent disguise artists and thieves, but need to use their actual Larceny ability if they wanna head up criminal organizations. -TheMyriadOfShades
Just wanted to say that this is quite wonderfully written, and actually rather inspirational - reading these interpretations of Lunar abilities has given me a fresh hand of ideas of how to use Lunars in my games. Bravo! ...DeathBySurfeit
I can see some very impressive Larceny stunts to keep underlings in line involving comments like, "Maybe you've heard about feeding people to pigs? I don't do that. You step the wrong way and I'll just eat you myself." Lunars - the brains and muscle of the outfit since RY -1378! - Kurulham