- "The Keepers seek to exploit the weakness between the dimensions, to allow their master's passage to this world, you must repel their onslaught at all costs!"
- — The Shadowman talking about the Keepers.
The Keepers, also known Angels (known in their own language as Kreeholo), are mystical creatures in Call of Duty: Black Ops III and Call of Duty: Black Ops 4 that play a major role in the storyline of Zombies. They first appeared Shadows of Evil, Der Eisendrache as a part of the main Easter Egg, Zetsubou No Shima, and Revelations. They are mentioned in Call of Duty: Black Ops 4 by Richtofen in Blood of the Dead and seen in the Alpha Omega intro, as well as the Tag der Toten outro.
The Keepers are ancient unearthly creatures, said to come into existence in the beginning with the Aether. The Keepers created the Summoning Key, the most powerful device in this or any other universe, which they used to create Agartha, a physical manifestation of the Aether. A Keeper known only as "The First One" would use the Summoning Key at some point to seed the various dimensions with life. The Keepers, sometimes known as the 'Order of the Keepers', are responsible for preventing the Apothicons from wrecking havoc upon all dimensions through time and space. The Keepers are associated with the Ancients, who carry on them the same sigil of the Black Sun.
A small contingent of the Keepers started experimenting with the Dark Aether, among whom would be known as the Shadowman. These experiments culminated in the creation of the Aether Pyramid, which allowed its user to control reality itself. During the Shadowman's corruption, his best friend, who would come to be known as Doctor Monty, attempted to save him but became corrupted himself in the process. After this, the corrupted Keepers waged civil war on their brethren. The corrupted Keepers were defeated and those who remained were banished into the Dark Aether, afterwards the Keepers ascended to become the wards of all reality. As time went on in the Dark Aether, the corrupted Keepers were slowly morphed and changed into the Apothicons, barely resembling their former Keeper selves. During the middle ages, the Apothicons found a way to re-enter creation and attacked the Earth; beginning The Great War. With the help of the mankind and four strange staff wielding knights, the keepers were able to defeat the Apothicons and banish them from their world once more.
In Shadows of Evil they at first try and fail to prevent the characters from following the Shadowman and using the Summoning Key to obtain the Gateworms and open the Apothicon rift stone. Later they aid the crew, providing them Keeper swords, trapping the Shadowman into the key and killing the beast in the sky. Just before a Keeper passes the Key to the crew, it gets stolen by Edward Richtofen. The Keepers can also been seen in the wall-run in the sacred place, fighting alongside Primis who use the elemental staffs in the Great War.
In Der Eisendrache, Primis summons one Keeper from a tomb using the Vril Device and aids it in returning to its physical form. In return, the Keeper transports the M.P.D. from the Moon to the castle, but gets corrupted on the way. After a battle against the corrupted Keeper, Primis manages to cleanse it. In Zetsubou No Shima, several Keepers attack the player when attempting to pick up the Skull of Nan Sapwe, but get dispatched by the group. In Revelations, corrupted Keepers appear, and the Keeper logo on their chest is now the Apothicon symbol for curse. A Keeper Protector also appears, which assists Primis in repelling the Apothicons during their second invasion of Agartha.
In Tag der Toten, the remaining uncorrupted Keepers were merged with the Apothicons to form one species inside of the Aether again, resolving the duality between the two thanks to Victis crafting the Seal of Duality. They were banished, alongside everything else, to the Dark Aether after Primis Nikolai destroyed the Summoning Key and killed the rest of Ultimis and Primis.
The Keepers appear as some sort of unearthly species of unknown origin. They have large sharp teeth and no visible eyes, similar to the Margwas, and have three clawed fingers on each hand. They don't seem to have legs, but instead levitate. They wear dark red robes with gold embroidery including the Order of the Keepers symbol on their chests. Once in contact with the Dark Aether, the Keepers get corrupted, they turn into a purple color, Apothicon symbols replace the Keepers symbol on their chest, and then they eventually turn into Apothicons like the Margwas and Parasites.
- The symbol of the Keepers, the Black Sun, is based off of (although not an exact replica of) the Schwarze Sonne, a symbol featured in one of the rooms in Wewelsburg during Heinrich Himmler's ownership of the castle. It is most commonly associated with Nazi occultism and some sects of Satanism.
- In Der Eisendrache in the pyramid room, the pillars surrounding the pyramid are shaped to resemble four Keepers.
- The Keepers have a sword or a dagger on their back.
- The symbol on the chest of the Corrupted Keepers in Revelations is the Apothicon word Ullamargor, which translates to "curse".
- Primis collectively hold the Keepers in great respect, with each character showing their displeasure in having to kill Corrupted Keepers in Revelations.