Shadow's HeartWeapon 18
Source Pathfinder Core Rulebook
Damage 1d6 Slashing
Type Martial
Price 23,000 gp
Weight light
This +3 greater striking kukri has a thin, delicate blade that absorbs light.
Activate 
Interact (illusion, teleportation)
Frequency once per day
Effect You make a melee Strike with shadow's heart and teleport to an open space you can see within 100 feet. If the attack hits, you also leave behind a shadowy, illusory duplicate of yourself that attacks the same target for up to 3 rounds. The illusion has 1 action per round, which it takes on the turn it's created and on your turn each round. It uses this action to move up to 30 feet to a square adjacent to the target and (if the target is adjacent) to attack the target with a +28 attack modifier, dealing 3d6+16 slashing damage. The illusion has an AC of 35 and is immediately destroyed by any attack that deals damage or requires a saving throw.
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.
AgileThe multiple attack penalty you take with this weapon on the second attack on your turn is -4 instead of -5, and -8 instead of -10 on the third and subsequent attacks in the turn.
EvocationEffects and magic items with this trait are associated with the evocation school of magic, typically involving energy and elemental forces.
FinesseYou can use your Dexterity modifier instead of your Strength modifier on attack rolls using this melee weapon. You still use your Strength modifier when calculating damage.
MagicalSomething with the magical trait is imbued with magical energies not tied to a specific tradition of magic. A magical item radiates a magic aura infused with its dominant school of magic. Some items or effects are closely tied to a particular tradition of magic. In these cases, the item has the arcane, divine, occult, or primal trait instead of the magical trait. Any of these traits indicate that the item is magical.
TripYou can use this weapon to Trip 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 Trip using the weapon, you can drop the weapon to take the effects of a failure instead of a critical failure.