For over 30 Years the Omega population has been declining Rapidly. And all kings that rule over Sina, Trost, and Rose are all Alphas.To fix this a law is passed. To have a offspring for the king, as well next heir for the throne. All the towns must bring every omega in there distract and to whom ever is chosen by the king is to be married off to him and bear his off spring. No exceptions, no doubts and just the odds to be in your favor. For Eren much of the odds were not with him as he gets picked for the next queen of the kingdom. And bear the child of Levi Ackerman the 104th of the land.