MTL - Vanguard of the Eternal Night - Chapter 138

Feng Ming was only 19 when he lost his life saving a child from death without hesitation. The grateful father of the rescued child grants Feng Ming a second chance at life. Unknown to Feng Ming, his soul has whisked away to a far away ancient land (resembling the dynasties of China).

An ordinary (?) grandfather, Choi Chuntaek. In an effort to protect his granddaughter, he started the virtual reality game 'Arkstar.'

Then... he accidentally obtained a legendary class?

Qiao Shao, who worked hard to stay up all night and study, was first in class — if you count from the bottom.