Rebirth As a Fatuous and Self-indulgent Ruler - Chapter 23 - “Father!”

In his past lifetime, he was an exceptional prodigy who practiced both medicine and martial arts. In this lifetime, on earth, he used his superb medical expertise and extreme martial arts achievements from his past lifetime to excel in the medical field and the ancient martial arts world. He moved his way towards the pinnacle!

An ordinary youth living in the year 2050 in the Western calendar accidentally came to a fantasy world created by the collision of magical elements and supernatural technology at the other end of the dimension…

- Description from novelbuddy

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?

One day, I was summoned to this world.