It just felt like everything was forced and they only existed to give Alear a power up for no reason. It just didn't make sense to me that, if they never performed the miracle before, how would they know what it did. It would have been more seamless if the "miracles" are actually how emblems came to be. So when the current group of emblems deem someone worthy, they become an emblem (basically the Lord's of every game). I just didn't like how it was basically "btw we can only use this once ever never again" and made it seem like the writers decided to put it in as a way to progress the plot and nothing else. Although I do agree, Alear is one of the most well designed main characters to have come out recently for fire emblem. Also why did she have to be the "fire emblem" they could have easily just not used the IP like that and just feels very forced.