After a character connected to the Jinni triggers an Electro-Charged, Superconduct, Overloaded, Quicken, Aggravate, Hyperbloom, or an Electro Swirl or Crystallize reaction, the CD of Spirit-Warding Lamp: Troubleshooter Cannon is decreased by 1s. This effect can be triggered once every 3s.
It's probably the free event weapon of 5.6, which rarely have good passives. This one is just a bet...