MTL - Back to 70 to Marry Unlucky Male Partner - Chapter 43 first letter

Takebayashi Ryouma, a 39 years old man with hidden past, found himself in a strange white room. The gods tell him that he has died and that they are sending his soul to a different world, a world where magic exists. After living alone for 3 years, his gamer soul loses its common sense and starts along crazy routes.

Sam crosses to a new planet that is completely magical. He discovers that humans can have superpowers, and monsters also inhabit the planet. Humans continuously fight these monsters to protect themselves and their world.Unfortunately, Sam, who just arrived on the planet, lacks the potential to become powerful and doesn't possess any shortcuts to gain strength quickly. As a result, he resigns himself to living an average life and tries to avoid danger.However, everything changes when he graduates from the academy. He receives an invitation from his former academy to become a teacher, and simultaneously, he awakens the Teacher system.Now, on this perilous planet, if he desires to become powerful, he must accept students and empower them. Only when his students become strong will he gain strength himself. Join his journey to become the greatest teacher.

I am Master Siwei, and I speak for arcane arts.
This is an era of heroes and heroines.
This is an era of great changes.
In the end, it will be an arcane era opened by me.

- Description from Novelupdates

Freshman student Yang Dingtian possesses the Nine Yang Body, found only 1 in million. His Yang Fire is incomparably vigorous and thus, he cannot be near a female’s charms for his entire life. On the night of his 19th birthday, he decided to bid farewell to his virgin life. After stealing and tasting the forbidden fruit, he spontaneously combusted as the result!