These Marines were created during the Heresy itself. Rushed into production to meet the demands of war, they were fully commissioned warriors after only 4 years of training and modification. Though suboptimal to the carefully cultivated Space Marines of the Great Crusade, they were still formidable fighters and were utilized by both sides. The production and training of Newbloods was more unstable and dangerous than normal, and even more Aspirants died during the process than normal. As such, they were often known for their savage and brutal nature.