Albus needed a muggleborn friend for John and Akira, so that everyone could see that the boy-who-lived was associating with muggleborns. And with Akira to make sure the girl was powerful and influential in the magical society. With how the girl behaved, Albus had seen that with her behaviour the girl had the same resemblance as Lily. Albus was sure that he was not going to fail. The girl would also have been the perfect baroness Weasley, but since Arthur found out about everything, this plan had been delayed. She would be the perfect muggleborn minister and with Ron being the head auror, John being the head of the DMLE and Akira under his control with his seats, Albus would have complete control over the ministry and the Wizengamot. The light side would be ruling again, but firstly, he needed to get Akira under his control, but the question was how?