The Design (3)
The Colonial-designed Centurions used artificial intelligence, and were designed as sentient beings. By the time the first war ended, they were already practitioners of a religion centered around what would come to be considered the "Cylon God" ("No Exit").
Saul Tigh, who possessed false memories of the First Cylon War, recalled the Cylon boarding of the Brenik, and the apparent hatred the Centurions had for humanity - despite the physical inability of the Cylons to show emotion on their faces (deleted scene from "Scattered"). This reflection of animosity and intensity is also apparent in the stylized Monclair painting in William Adama's quarters, depicting Cylon War-era Centurions battling Colonial forced utilizing relatively primitive weapons ("Islanded In a Stream of Stars ").