Blasphemous Icon is a Warriors of Chaos military recruitment building in Total War: Warhammer. By planting an icon in the ground, a siren call is sent forth that Chaos Warriors must heed.
Background
Summoning the many minions of Chaos is a power even the lowliest servant has. Whether a Greater Daemon, a familiar, or the iron-clad warbands of the Chaos Warriors, there is always some method or ritual. For Chaos Warriors who are not led or sent by dark wings, one way is to plant a blasphemous icon in cursed ground. A sonorous call will spread, drawing Chaos Warriors and fell beasts to its source.