Xander is a major playable character from Fire Emblem Fates on the Conquest and Revelation routes. The eldest of the Nohrian royal siblings, Xander is the crown prince of the country, commanding the loyalty of Laslow and Peri as his personal retainers. If Xander achieves an S support, he will bear a son named Siegbert with his spouse.
(Source: Fire Emblem Wikia)
