MTL - Open a Clinic to Cultivate Myself - Chapter 21 Jianghu Youyi

After a mishap, he accidentally became the protagonist. Unexpectedly, he and the villain cultivated together and they actually became dao companions.

“If you want to be with me forever, there is only the supreme road of achievement. Are you willing to travel with me?”

“Of course I’m willing.”

……

In Li JinZhi’s view, the protagonist and villain’s coexistence should be like swords and spears facing each other, a feud.

But when he crossed into the novel and became the protagonist; when he placed all his trust in the man who was supposed to be the villain; when the other side revealed some unusual feelings to him; when he held Ye Yu’s hand to the altar, he discovered that the relationship between the protagonist and villain isn’t as dull as he imagined.

When the monotonous pattern is broken, the feelings of resentment turns into sharing a common destiny.

- Description from Novelupdates

Elias' world was destroyed right in front of his eyes. Only after his transmigration did he learn that there was nothing natural about its destruction.“Mother, I passed my Practical Exams! I was so lucky to get a weak world like Earth for my practicals! It only took a few months!”The person who destroyed his world was the eldest son of the family he was transmigrated to, the Ashborns.He could never forget his sister's cries when she suffered and eventually died from the virus that wreaked havoc in his world. And here he was, the person responsible, laughing.Elias wanted to repay the favor. He wanted to bring absolute ruination to these people. And for that, he had to play by their rules. He had to become the Architect of an Apocalypse…

The tale of Oliver.
An orphan boy from a Mine, in 19th century Europe, filled with Magic.