What does Mythic Guardian ability partial transformation allow?

Question

So the game I am playing a druid in has unexpectedly granted us a mythic tier. Im told that this will be the only one we get so many of the abilities that become more useful as you gain tiers, kindof suck. So choosing one has been hard and I have finally decided that partial transformation looks pretty good. The problem is that it doesnt actually define what it can do very well.

Partial Transformation (Su)

You have refined control over your transformation ability. When using wild shape, you can expend one use of mythic power to only partially transform into or out of animal form. For example, you could transform your hands into tiger claws and your head into a tiger’s head (giving you low-light vision and scent, and allowing you to make claw and bite attacks but still wear armor and use worn magic items normally), transform into a deinonychus with human hands (allowing you to still manipulate objects and wear rings), or transform into a constrictor snake with a humanoid head (allowing you to speak and cast spells with verbal components). You may make one such change per round as a free action for the duration of that use of wild shape.

For example, if you change into a tiger, this ability allows you to partially transform yourself from tiger form to your normal form and back as needed until the duration ends or you fully return to your normal form. You must have the wild shape class feature to select this ability.

So particular aspects of a form are allowed. Can I use the ability multiple times gaining abilities from various animals? Could I wild shape into an octopus, then shift to give those arms claws and rend?

So to what limit am I restricted to? Can I take size, attacks, or senses?

Answer 1

This ability allows you to gain the mechanical effects of Wildshaping while keeping also the mechanical effects of your normal form. Basically, you can take the better for everything and fluff it so it works. If your normal form had rend (for example because you are a cat), then you could partial shape into an octopus and give it rend (maybe the tentacles all end in a cat's paw). However, you can't partial shape multiple forms, because you can't wild shape into multiple creatures at the same time. You only get to pick parts from your target form and your base form, and you keep the same target form for the duration of your wild shape.

If another ability allowed you to use multiple target forms at one, however, such mix-and-matching would be possible. Most effects along those lines, however, would already overwrite form restrictions on the transformation, for example the way Rakshasa's Fortune does.

Answer 2

You would still be restricted to Wild Shaping into one other form (partially) because you cannot Wild Shape from being Wild Shaped, it is not a stacking buff. When you Wild Shape into an animal, even partially, you are Polymorphed and Wild Shaping again will leave you, partially, in the new from removing the 'old' affect. All of the examples given are 'or's not 'then'.

From Polymorph:

You can only be affected by one polymorph spell at a time. If a new polymorph spell is cast on you (or you activate a polymorph effect, such as wild shape), you can decide whether or not to allow it to affect you, taking the place of the old spell. (...)

Emphasis added.

AFAIK you are not restricted by size... but that's largely up to GM interpretation. I can't imagine altering just your hands to be Huge Claws, but there is no verbage against that.