What greater Knack could there be than the potential to change into any shape at will? The Exalted is marked with the secret Primordial Word for Luna. By activating this Knack they can transform their whole being into sentience and moonsilver.
   This Knack allows the Lunar to maintain a physical form, which is basically made out of Wyld Essence, while in the Wyld. In this shape they can hunt through the Wyld and engage in physical combat while within it. Pure moonsilver Warstriders can also accomplish this.
   Those who are individual and mindful enough to accept them are given Lunar Exaltation. They are given apparently limitless power to make themselves anything they desire. Their natural realm is the Wyld and it's their task to endlessly hunt it for Fair Folk who threaten Creation as Luna did before them.
   A full carapace of moonsilver can allow a warrior to maintain a physical form of sorts in the Wyld rather than having to transmute themselves into an abstract notion as the Lunars are capable of doing (turning their own identity into an abstract notion) to exist within the Wyld without their physical form being ruined. Maybe this is the true significance of their Spirit Shape. Ghosts, gods and demons can exist as Essence and naturally belong in other dimensions. Lunars can do the same thing. Their Spirit Shape is a Wyld Essence pattern formed expressing their own identity by the transmuting power of the Lunar Essence within them. They can exist in Creation in this form but naturally belong in the Wyld in it. It can exist as a coherent identity within the Wyld. The only thing other than a moonsilver form that can do so.

The Animals That Grow In Five Places

    Terrestrial Exalted are Aspected after the animals that live in one of the five Elements. All Dragon-blooded have a totem creature that embodies one of the aspects of the Dragon they are descended from. When they start to spend peripheral Essence their anima, their totem creature, starts to manifest.
   Maybe being locked into beastman form is the effect of Lunars manifeesting their anima as exhibition of their powers reveals their true form. Their Spirit Shape is what they really are. Maybe they always are their Spirit Shape and what they appear to be is just an illusion. Their Spirit Shape is the shape of their spirit, their Essence.

Beastman Transformation

    30th March Beastman Transformation doesnt have to transform into a war form. Beastman doesn't mean a crude combination of a human and animal. Becoming a beastman means transforming into a humanoid version of an animal that can speak with humans. They can learn beastman forms for other animals with additional Knacks. Beastman transformation means becoming a much more elegant combination of animal and human that is mostly animal. Like Chihiro in Little Norse Prince. Their beastman form is their natural spirit shape. They can express themselves through facial expression as well as speech, walk on two legs or move like animals and have unusual dexterity with their paws. When in their natural forms they do not use their moonsilver tattoos so these are less visible.
   Their alteration of Attributes while in animal form, possibly to the detriment of values makes them more dependent on Abilities. Should they have Ability based Charms?

Knacks III

    Any Knacks the Lunar knows relating to their spirit shape are automatically in play when the Lunar assumes it without Essence or Willpower cost.

    One of the greatest advantages of Knacks is they go on until the Lunars decide to reverse them. The Lunar can simply have a Knack and live with it as a personal enhancement to their capabilities. In fact they often gain reputations and are recognised by their unique combinations of Knacks they leave in effect.
'The Tell.'

    The use of Knacks is mosst obviously being able to use the beneficial traits of an animal without having to assume it's form. Knacks allow selected traits to be used in any form whether human or animal. They can stack Knacks using a variety of them at any time and don't suffer drawbacks from the creature they're based on. For instance Man O' War Touch is very useful but a jellyfish isn't going to live long on land.