Activision and Sony have together revealed an all-new Zombies mode debuting in Call of Duty: Black Ops Cold War that will be exclusive to the PlayStation 4 and 5 for just under a year, meaning Xbox and PC players will be missing out on a bit of the fun.
A part of the on-going partnership between Activision and Sony, which includes offering timed exclusive content on PlayStation platforms first for multiplatform games, Onslaught is basically a horde mode where you and one other player need to survive increasingly difficult waves of zombies.

Maps will bring the zombie curse to a wide variety of familiar locations from the game - this probably means that maps from a regular horde mode are going to be recycled - for this 2-player co-op mode. Custom Loadouts will be used here just as in Multiplayer and other Zombies modes.
Movement will be restricted at the start of the match by a Dark Aether Orb, so you'll need to find a good place to hunker down within that restricted area. Beyond the borders of the Orb you will continually take Dark Aether damage. As you slay more and more undead, the Orb will be powered up and move - making more resources available.

