Byleth Eisner

Byleth is the main character of Fire Emblem: Three Houses as well as the player customized avatar of the game. Byleth is a member of a band of mercenary led by their father Jeralt. After discovering a mysterious power hidden within, they are offered a post as a teacher at the Officer's Academy of the Garreg Mach Monastery. As such, they are the teacher of most of the playable characters in the game.