Doctor Player - Chapter 503

It has been a year since Li Fuchen lost his “talent”. Now he lives the life of a wastrel, being bullied and beaten by those who were once inferior to him. However, he has still not lost everything as he is engaged to a strong and pretty girl of a powerful family… but that came to an end as the engagement was abruptly anulled. With shame brought to the family and his life engulfed by darkness, a ray of hope pierced through the sky.

Civilization is destroyed and records lost. Only Dudian survives in a cryogenic sleep. Three hundred years later, Dudian wakes up and must become Dean to survive. Who can he trust in this world overrun by monsters without and within?

- Description from Novelupdates

A decade ago, the first dungeon gates appeared, but some vanished before they were ever conquered. The MC, a low-rank hunter, awakens the Lost Gate System, granting him access to these forgotten dungeons where legendary monsters and artifacts are trapped. Each completed lost gate grants him absurd power, but also reveals terrifying truths—these dungeons are prisons for ancient beings who want revenge.