I was going through my hard drive and stumble upon this magical item I had written up for the 2015 RPG Superstar contest.
Numerian Smart Sword
Aura moderate transmutation; CL 9th
Slot none; Price 21,100 gp; Weight 16 lbs.
Inspired by Androffan smart armor, the Technic League developed a multi-function smart weapon. This +1 adamantine greatsword has active and inactive modes. While inactive it functions as a medium greatsword; however due to its great weight applies a -2 penalty to attack rolls, to any medium creature wielding it two-handed or any large creature wielding it one-handed. It can activated as a swift action, expending one charge, expanding to a large greatsword and negating any penalties related to the size; thereby, allowing a medium creature to wield it as a two-handed weapon with no additional penalties. While active it consumes one charge per round, and it can further change form as a swift action like a transformative weapon, consuming one charge and choosing from glaive, greataxe, spiked chain, or two-bladed sword, all large-sized.
Like smart armor, it has 60 charges. As a hybrid weapon the enhancement bonus to attack and damage rolls and the negation of the size penalty are affected by areas of antimagic or similar effects, but not its transformative properties, those being limited by its charges.
Requirements Craft Magic Arms and Armor, Craft Technological Arms and Armor (DC 30), bull's strength, lead blades, righteous might or giant form I, military lab; Cost 11,635 gp
The Garland Ancient Polymorphic Weapon
Price 21,100 sp; Weight 16 lbs.
This heavy matte black sword appears to be forged from one solid piece of metal with a repeating fractal pattern etched over its entirety. It is clearly a work of craftsmanship beyond that currently available, but at the same time despite the intricacy of the etchings, it looks and feels extremely utilitarian, much like a munitions grade sword. It is in fact a product of the ancient Numerian Empire as an attempt to copy and improve upon even more ancient wonders of the Androffan Technocracy, specifically the so called "smart armor."
This adamantine greatsword has two modes, active and inactive. While inactive it functions as a greatsword; however, due to its great weight it applies a -2 penalty to attack rolls. It can be activated as part of any action involving it, expending one charge, initially folding outwards into a larger greatsword (d12 damage) and negating any penalties related to the size. While active it consumes one charge per round, and its form can be changed once per round without using any additional actions by consuming an additional charge, choosing from glaive (d10 damage), greataxe (d12), spiked chain (d8), or two swords (d10 damage), all larger than human sized.
It possesses 60 charges of a technological nature; therefore, it can only be recharged by means of radio-isotopes, extremely pure (and volatile) chemicals, or strong continuous electric current. When out of charges it reverts to its base form of a serviceable, if clumsy, greatsword.
The Garland is the product of both foreign super-science and ancient magic, a necessity for despite how advanced the Numerians were, they were never able to reach the same heights of technological wonder that the Androffens did. Instead they 'cheated' using magic to fill in the gaps. It counts as a magic weapon for all matters that care about such things, although it does not provide bonuses to attack or damage rolls.