Now that Rein had told all his wives about what they needed to do in order to fulfill their wish, they all started to make preparations for just that. At the same time Rein was also making preparations as there was something he also needed to do to fulfill his own wish.
Obviously Rein wanted to reach his own full potential but currently he was only just over 20 years old. He was still very young and had a lot of time to reach his potential. Quickly becoming stronger was not always a good thing and currently he needed to slow down a little bit.
So what did Rein want if not to quickly grow ? He actually wanted to find a way to increase his potential. He already had a high potential but after meeting Anna he understood that it might not be good enough to take him to the absolute peak. So he wanted to know if there was a way for him to make his potential stronger.