Inigo (Azur in the Japanese version and Íñigo in the Non-English European versions) is a playable character introduced in Fire Emblem Awakening and returning in Fire Emblem Fates under the alias Laslow (Lazward in the Japanese version). His birthday is on August 7.
He is the son of Olivia, and a character from the future. In Awakening, he can be the brother of Lucina or Morgan, depending on if Olivia marries Chrom or the Male Avatar. In addition, he can also be the father of Morgan if the Female Avatar marries him.
In Fates, he is the father of Soleil. He can also be the father of the Male Kana or Shigure, by achieving a S-Support with the Female Avatar or Azura (respectively).
(Source: Fire Emblem Wikia)