Along with Vampiric Powers, 5 new Endgame Bosses, and a host of quality-of-life improvements, the second Season of Diablo 4 will also introduce players to a new open world Event – called Blood Harvest.
Season of Blood Livestream Summary Diablo 4 Season 2 Official Blog Post
Home to the highest chance for receiving Potent Blood and Pact Armor drops is the Blood Harvest Seasonal Event.