GearbladeWeapon 17
Source Pathfinder #161: Belly of the Black Whale
Damage 1d10 Bludgeoning
Type Martial
Price 13,000 gp
Weight 2 bulk
Shaped like a blade made from spinning gears, this +2 greater striking weapon can catch enemy weapons and grind up foes. In order to function, the gearblade must be wound for 10 minutes once every 24 hours. During this process, you can reconfigure the weapon to transform into a bastard sword, greatsword, longsword, or shortsword. It then gains all the features of the chosen weapon except that its Bulk is always 2 and it gains the disarm weapon trait and the versatile B weapon trait (which replaces any other versatile trait the weapon might have). If you don't wind the gearblade, it becomes inert and has the statistics of a greatclub.
Activate 
envision
Frequency once per day
Requirements You've wound the gearblade for 10 minutes within the last 24 hours
Trigger You roll a critical success to Disarm a target with the gearblade
Effect The target's weapon is pulled through the gearblade's gears and shoots out the other side, landing 20 feet away in a direction of your choice. The target must attempt a DC 36 reflex save. On a failure, the limb holding their weapon is also pulled into the gearblade, and the creature takes 3d12 bludgeoning damage. On a critical failure, they take 6d12 bludgeoning damage and the limb becomes unusable until healed by a Regenerate spell or a similar effect.
Traits
This rarity indicates that a rules element is very difficult to find in the game world. A rare feat, spell, item or the like is available to players only if the GM decides to include it in the game, typically through discovery during play. Creatures with this trait are rare. They typically can't be summoned. The DC of Recall Knowledge checks related to these creatures is increased by 5.
BackswingYou can use the momentum from a missed attack with this weapon to lead into your next attack. After missing with this weapon on your turn, you gain a +1 circumstance bonus to your next attack with this weapon before the end of your turn.
ClockworkClockworks are intricate, complex constructs that can be programmed to perform specific functions.
InvestedA character can wear only 10 magical items that have the invested trait. None of the magical effects of the item apply if the character hasn't invested it, nor can it be activated, though the character still gains any normal benefits from wearing the physical item (like a hat keeping rain off their head).
ShoveYou can use this weapon to Shove with the Athletics skill even if you don't have a free hand. This uses the weapon's reach (if different from your own) and adds the weapon's item bonus to attack rolls as an item bonus to the Athletics check. If you critically fail a check to Shove using the weapon, you can drop the weapon to take the effects of a failure instead of a critical failure.