The preorder bonus is this companion. But what exactly is this companion? Does it take the place of the illlusions we received in the last two expansions? Or is it like a familiar and takes the place of familiars? Can we use this as well as clockwork or the other one? Does it stack with anything? Or does it take the place of both our familiar and the present illusions? Please explain. I am trying to determine where to order or not? And how many accounts to order for?