will have a reason to be happy in patch 4.3 (due to be released whenever.) There’s a pair of Legendary Daggers that will be available. No lore is available yet. Expect tweaks to this item before it’s released and maybe after, as well. The existence of the new daggers has been known for awhile, but there’s a bit more new info, below.
WoWheadNews has this in their post:
Fangs of the Father: Legendary Proc
Shadows of the Destroyer: Increases your Agility by 17, stacking up to 50 times. Once you have acquired 30 stacks of Shadows of the Destoyer, each stack gained grants an increasing chance to trigger Fury of the Destroyer and cancel all stacks of Shadows of the Destroyer. Fury of the Destroyer immediately grants 5 combo points and causes your finishing moves to grant 5 combo points. Lasts 6 sec.
Legendary Wings: No further information on it yet, but probably related to the cosmetic effect of unfurling wings.
We’ve known for a while that the weapon will have two earlier stages like the previous legendary did, but now there’s some more information on them. Both of them also have procs:
The original post has a lot more info on 4.3, DK tier 13, Chromatic Dragon, and more: Patch 4.3 – PTR Build 14890 – Spell Changes, Fangs of the Father Legendary Proc, and More!