Nemesis

Nemesis is a character from Fire Emblem: Three Houses.

Profile
Nemesis was the leader of an army that opposed Seiros and the Ten Elites during the War of Heroes. He possessed the Crest of Flames, and wielded the Sword of the Creator. In Imperial Year 91, the armies of Nemesis and Seiros clashed at the Tailtean Plains. There, Nemesis was confronted and slain by Seiros in single-combat.

Etymology
Nemesis is the ancient Greek goddess who enacts retribution against those who succumb to hubris (arrogance before the gods). Another name for her is Adrasteia (or Adrestia), meaning "the inescapable"