Etna's Lost Dagger is a Unique Dagger in Diablo IV Season 15 for Rogue. It drops from Harbinger of Hatred.
Unique power
Dealing 2 different types of Non-Physical damage increases the Potency of your Imbuement Skills by [45 - 60]% and Non-Physical damage by [45 - 60]% for 8 seconds. Basic Skills are now Imbueable.
Affixes
Ranks to Imbuement Skills (+1-2)
Where it drops
Harbinger of Hatred (Harbinger's Den, Nahantu; requires Vessel of Hatred) - Greater Lair Boss, 2x Mythic drop rate (boosted/targeted drop)
Belial, Lord of Lies (Palace of the Deceiver, Kehjistan) - mimics any chosen boss loot table, guaranteed Ancestral Unique, highest Mythic chance