The material below is Open Game Content from Legendary Blades
Transformative This ability can only be placed on a melee weapon. A transformative weapon alters its shape at its wielder’s command, becoming any other melee weapon of the same general shape and handedness; the weapon’s categorization as simple, martial, or exotic is irrelevant. For example, a Medium transformative longsword can take the shape of any other Medium one-handed melee weapon, such as a scimitar, flail, or trident, but not a Medium light or two-handed melee weapon (such as a Medium short sword or a Medium greatsword). It can even take the shape of comparable weapons of different size categories.
For example, a Small greatsword is a two-handed slashing weapon for a Small character, but is a one-handed slashing weapon for a Medium character, which is very similar to a Medium longsword; a Small transformative greatsword can become an actual Medium longsword, usable by a Medium creature without the –2 penalty for using a weapon of the wrong size. The weapon retains all of its abilities, including enhancement bonuses and weapon properties, except those prohibited by its current shape.
For example, a keen transformative weapon functions normally in the form of a piercing or slashing weapon, but cannot use the keen property when in the shape of a bludgeoning weapon. When unattended, the weapon reverts to its true shape.