In Diablo 4, you will need to use Unique weapons and ... that drop from Whisper Caches and Grotesque Debtors at the Malignant Burrow under the Tree of Whispers.

Cycle through a malignant bonus every 20 kills: Vicious: Gain 21% Attack Speed. Devious: Core and Basic Skills have a 16% chance to fully restore your Primary Resource. Brutal: Every 20 seconds ...