MTL - Card - Chapter 566 cave

One day, I was summoned to this world.

Xiao Yi, an orphan raised by a disrespectful old man, possessed mysterious ancient martial arts and a unique skill in traditional Chinese medicine. At the age of twenty, he suddenly received the most baffling mission from the old man: to attend the renowned first-tier university, University Z, as a student, initiating his spectacular modern urban life. In the city, he began to write his own eternal legend...

After an unexpected death, a soul finds itself reincarnated into the body of Itsuka Shido, an ordinary teenager in a world filled with powerful spirits, magic, and dangers from other dimensions. With the help of a mysterious system integrated into his body, Shido gains the ability to travel across worlds, summon legendary anime characters, and unlock a wide array of random skills and abilities.Disclaimer: The cover isn't mine, credits to the original artist.

After the Catastrophe, every rule in the world was rewritten.