Sorrow

Sorrow is one of the Kingslayers, the other one is Anguish.

Source
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Background

 * 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.