Spent 25 points or more in lower tier skills in the Bloodlust tree.
Killing an enemy causes them to explode with an Elemental Nova matching the element of the damage that killed it (Non-elemental damage will cause an explosive nova).
Nova damage is increased for each stack of Bloodlust.
Any Overkill Damage is also added to damage caused by an Elemental Nova.
Damage/Stack added to Nova: 5%