Complex sentence: They are huge and stupid but extremely loyal once introduced to the Imperial Cult--it's even said that those who fought as rebels in the Horus Heresy only did so because their superior officers lied to them about which side they were on.
Split into simpler sentences: They are huge and stupid but extremely loyal once introduced to the Imperial Cult. It's even said that those who fought as rebels in the Horus Heresy only did so because their superior officers lied to them about which side they were on.