The Kingslayers

The Kingslayers, Anguish and Sorrow, are the artifacts used by assassination rogues in World of Warcraft: Legion.

Source
The Kingslayers are obtained from The Unseen Blade.

Description

 * The orc warlock Gul'dan had these daggers made for his personal assassin, Garona. The blades are said to drink blood and inflict traceless poison, leaving little sign of their grim work: the perfect tools for an assassin. She used them to carry out countless atrocities while under Gul'dan's control, including the murder of Stormwind's King Llane, whom she had befriended. Afterwards, in anguish, she asked a trusted ally, Meryl Winterstorm, to help her hide the blades away in the hope that they'd never have to be used again.

Base
Hidden trait: Sometimes triggers a dialogue with repair vendor in Valdisdall in Stormheim that gives you 50 Artifact Power.

History
See Blood Ledger

Trivia

 * Before Legion it was a common speculation that Kingsbane (dagger) was the weapon that killed King Llane.
 * It is unlikely that Garona used these daggers during the events of Warlords of Draenor, as was never an ally of  and thus is unlikely to have crafted anything for him.
 * After their introduction, the Kingslayers were added to Garona's cameo in Ulduar during the fight against Yogg-Saron.
 * If Khadgar is approached with the Kingslayers equipped, he will react by saying one of several things:
 * say
 * say
 * say
 * Mr. Shackle comments on the weapons.