Once a ritual is begun, armies of an Unknown Skaven Clan may spawn nearby the ritual site, automatically at war with the faction that started the ritual. They may also be joined by Chaos or Norsca armies. They do not appear on the Diplomacy screen.
|vs. High Elf||vs. Dark Elf||vs. Lizardmen||vs. Skaven|
The Unknown Skaven Clan begins appearing during the third, fourth, and fifth ritual. They will often spawn alongside the Warriors of Chaos faction and begin to move in toward ritual sites. When arriving at a ritual site, they will attempt to lay siege or attack it directly if the battle heavily favors them. If they succeed, they will destroy the ritual site. They will not hesitate to attack any other settlements they encounter, however, instead of razing, they tend to prefer to sack them. Do be aware that they will occasionally set up undercities beneath any settlement they sack, and may attempt to launch a vermintide. These undercites can be destroyed normally if discovered, and can also be destroyed by wiping out the Unknown Skaven Clan entirely.
During the final ritual, once ten turns have passed, they will spawn a second wave of armies. Be ready for their spawning.