Demon Slayer : The Silent Journey - Chapter 6: Training arc 2

Even in his dreams, Li Tianming can’t stop himself from laughing! Why? Because, his family pets are all the Primordial Chaos Beasts of myth!

After the brutal loss of his beloved grandfather, Liam Hunter embarks on a harrowing journey into the heart of the Dark Forest, known as the Forest of Kyrell, with a singular goal: to gain the strength necessary to honor his grandfather’s memory and to never lose anyone dear to him again. At just ten years old, Liam is thrust into a world of darkness and malevolence, where he endures four grueling years of training and transformation. In this shadowy realm, he is reborn as a fierce warrior, driven by a relentless desire to eradicate every demon and ultimately confront the Demon King, Emrys himself. To achieve his formidable goal, Liam must forsake any emotional connections that could weaken his resolve. The once vibrant and joyful boy is transformed by his trials into a cold and unfeeling combatant, hardened by the harsh realities of his quest. This is the story of Liam Hunter—the last wielder of dark magic—whose journey through darkness and sacrifice will shape him into a force of vengeance and resolve.

One god, one faith, one world, one mage… I am the only mage in the world.

- Description from Ptwxz (translated)

He became a teacher at the best magic academy in the empire.
….For being mistaken for someone else.