Bingo! It is now called the even-less-inspiring "Master of Many Forms". And it offers no help in this matter.
Let's see...the shapechange spell allows you to gain supernatural abilities of new form, but you lose your own. It doesn't appear to allow objects, either.
I think we should break the object shape into a different ability.
How about:
Greater Shapechange (Su): An agathion may assume the shape of any creature. This functions exactly like the shapechange spell, except the agathion retains its own supernatural abilities while in its new form.
This might help with becoming an object:
Weapon Form: A battleloth can change to or from its weapon form as a standard action that does not provoke an attack of opportunity. While in its weapon form, a battleloth functions as a weapon of the appropriate type with the indicated enhancement bonus. It can use only those movement forms and attacks specifically noted in its weapon form description, but all of its special qualities apply to both its weapon and its humanoid forms. A battleloth can perceive the world around it and can communicate normally while in weapon form. Since it lacks limbs, however, it cannot use spells that require material or somatic components.
In all other respects, the battleloth functions as a creature, not an object. It gains no hardness or additional hit points in weapon form, and any spells, attacks, or effects that specifically target it are resolved as if they had been used against the creature's humanoid form except that the battleloth benefits from a +2 size bonus to AC.
Alternate Forms (Su): Conjured gingwatzims are assigned two additional forms by the magic of the spell that calls them. The animate and object forms are chosen and fixed when the gingwatzim is called and cannot be changed unless the creature is returned to the Ethereal Plane. The gingwatzim can assume one of its other forms or return to its natural form as a free action once per round. Often (especially in the case of less intelligent gingwatzim) their controller orders them to remain in one particular form.
In the form of another creature, the gingwatzim retains its own ability scores and other abilities, and its deflection bonus becomes a natural armor bonus. It gains none of the assumed form's ability scores or abilities in any way, and retains the immunities of its elemental type. Armor class and skill bonuses based on size (such as Hide) use the new form's size instead of the gingwatzim's normal size.
In object form, a gingwatzim cannot move itself or drain Strength using its touch attack ability, and it loses its deflection bonus. When it takes the form of a weapon, a gingwatzim has an enhancement bonus equal to the bonus that would bypass its own damage reduction. For example, a pakim gingwatzim, which has damage reduction 5/+1, that takes the form of a longsword is effectively a +1 longsword.