Magic weapons should rare. They should also be awesome. The sorcerous weapons below make good MacGuffins for an adventure. However, if a hero is going to use it long term it should probably cost them a schtick — either one gained through advancement, or replacing one they already have.
Sword of Biting (10)
This Dao, curved Chinese broadsword, is enchanted by the spirit or its original owner. It lusts to avenge those who critically injure or kill its wielder. While the sword is being used in combat, each time the wielder takes damage he can pay a Fortune (or derivative attribute) point to make an immediate counter attack. If the character is forced to keel over while using the Sword of Biting, the sword makes one final attack. This attack uses all of the character’s remaining Fortune points, and gets a +1 to the attack role for every point used in this manner.
Flying Guillotine (10)
A basket with a series of vaguely explained blades around the rim. When thrown over an opponent’s head, it decapitates them and allows the attacks to retrieve the head in the basket. In Feng Shui, it works as described against mooks. Against named foes, it is a damage 10 melee weapon, and the decapitation effect is a cinematic description of a killing blow. This weapon should not require a schtick to use.
If you want to see one of these in action, check out Season 11, Episode 7 of Mythbusters. I found the results surprising.
Sword of the Dragon King (10)
This ancient sword combines an intricately carved jade dragon hilt with a blade forged in a dragon’s fire. A character attacking with the sword can chose to use their Sorcery skill, instead of Marital Arts, for the attack roll.