The round-based mode in Call of Duty Black Ops 6 Zombies features a lot of blocked routes, locked doors, and removable obstacles. All of these can be accessed by spending the currency called Essence.
You can also spend the Essence currency in the Call of Duty Black Ops 6 Zombies mode to purchase Perks and Pack-a-Punched weaponry. These help you and your teammates survive for longer and exfil when the opportunity arrives.
You can earn Essence by slaying zombies of all types. Sometimes, vials of Dark Aether Essence will drop when you eliminate tougher enemies in this round-based mode of CoD Black Ops 6 Zombies.
Here is a complete list mentioning how to use Essence in the game:
- Access objective-related devices (these power the station) in Terminus to progress further and reach the end-game of the round.
- Unlock doors, some of which allow you to split the unlocking cost of Essence with a teammate.
- Summon a Tactical Raft for aquatic explorations and side content.
- Buy Perk-a-Colas from Perk Machines, or use Der Wunderfizz to access all Perk Cans on the map for Operator advantages.
- Upgrade weapons at the Pack-a-Punch Machine, which range from Tier I, II, or III, and increase power, ammo reserves, and receive special effects for current weapons you have.
- Use Essence to buy ammo from Ammo Caches.
- Purchase weapons of a higher rarity from the ‘Weapon Wall’ Buy spot.
- Upgrade a higher tier (Tier I, Tier II, or Tier III) armor from Armor Wall Buy.
- Use Essence to receive a random weapon with a very high rarity from the Mystery Box.
- Start a special Trial challenge for extra challenges and rewards.