Evolving items are usually released in generations, or "gens" for short. When a new EI arrives in the Cash Shop, the 1st generation is available for purchase, containing the starting poses for that item. After a time, the item will "evolve", and the starting poses will be replaced by the new second stage poses. At the same time, the 1st gen of that EI is no longer available for purchase from the Cash shop. If the EI is bought from the shop at this point, the purchaser will receive the 2nd gen of the EI, which will contain the starting poses. Each time the item evolves, a new generation replaces the old one in the Cash Shop until the item reaches its final stage.