Invincible Teacher - Chapter 90

Eren Idril died as an old, decrepit, and piss-poor adventurer by the maws of a D-Rank monster. He had a lot of unfulfilled dreams and desires that couldn't see the light of the day after the light in his own eyes died down.

But fortunately for him and unfortunately for the world, that wasn't his end. Eren was somehow dived back in time when he was a mere teen, attending Lionheart Academy for adventurers.

When life gives him a second chance, Eren decides to exploit it to its fullest. Experience his vile deeds as he partakes in them without feeling the slightest bit of hesitation.

Young Master Lu says, “My wife knows nothing at all and has a bad temper. You’d better not bully her.” Gu Mang watches silently as this man warns everyone who comes his way.

A surgeon accidentally got the blessings of a system, shocked the medical industry, and rejuvenated countless people.

- Description from Novelupdates