Aenir

Aenir is an Ice Dragon and the mother of Ninian and Nils. She is mentioned in Chapter 19xx of FE7, during a flashblack scene. A man who resembles Nergal speaks to two children, who seem to be younger versions of Nils and Ninian, and tells them that he will look for their mother, Aenir. In the English version, the man appears to refer to Aenir as a place.