This is the army of the Old Ones. I got the idea for it from the back of the necron codex. There is a scenario where it suggests that someone could make an old ones force using lizardmen. I took this idea and decided that the eldar had found the last traces of the old ones on some deserted planet or on an exodite world. The eldar, needing both knowledge and numbers, decided to teach the old ones their ways, including the way of war. This is the result and now the old ones are regaining a little power with their eldar allies.