User blog comment:SkyEyeKiller23/Yakshas and God Arcs Soldiers, Somehow related?/@comment-3505803-20140115171109

They are related in that they're both based on God Eaters. Yaksha Rajas are corrupted God Eaters who fell prey to Aragami. God Arc Soldiers meanwhile, are manmade creations that may or not use humans as a pilot. But they're not one and the same; when a God Arc Soldier goes corrupted, it turns crimson and not into a Yaksha Raja. You could say that the many Yaksha Rajas in God Eater 2 were for the sake of preparing for the real thing taken up to 11.