As the player roams the active Blood Harvest map, they will begin to find prisoners and Seeker Caches that require Seekers Keys to free and open.
You can also use any Seeker Keys you find to free prisoners of the Dark Master’s army or on Seekers Caches to receive Pact Armor, Pact Consumables, and Potent Blood.
Home to the highest chance for receiving Potent Blood and Pact Armor drops is the Blood Harvest Seasonal Event. With a wave of his hand, the Dark Master has dispatched cunning Blood Seekers with armies of vampires to conquest the Dry Steppes, Hawezar, and Scosglen regions of Sanctuary, imprisoning its denizens and causing pandemonium.
Putting enemies to the sword during Bounties, bursting Blood Blisters, completing World Events, disrupting vampiric rituals, and freeing prisoners, will earn you some Reputation. With Reputation, you’ll climb Tiers containing useful rewards, such as crafting materials, Items, and Pact consumables.
Inside the Blood Harvest, you’ll have the chance to acquire Blood Lures, which summon Blood Seekers for you to extinguish. You can also use any Seeker Keys you find to free prisoners of the Dark Master’s army or on Seekers Caches to receive Pact Armor, Pact Consumables, and Potent Blood.