A spoiler about what happened to Tessetan in Korea (1st timeline)
Spoiler!
He really died. He got impatient in earning money because Tie is already growing up. And because he's a foreigner, he can't find a proper job. And as a father, he only want to give the best for his daughter. So when he was offered a work, even though he knew it was illegal, he agreed. He worked in a illegal seafood processing workshop. So there were no building permit whatsoever. The tragedy Tessetan experienced is being locked in in a cold room/walk in freezer until he died. It was also narrated how he struggled when he first arrived in Korea. Our poor guy didn't have the protagonist buff and suffered a lot in a strange land without any knowledge or guide. He was chased, scammed, and learned everything by himself. Plus even his looks became a problem. Things got better a little when grandma neighbor helped him but he still had a hard time earning money.
I like to post spoilers for the stories I find interesting because I don't have much time to read novel due to busy schedule you will find me in most romantic historical manhwa comment sections
but I also started reading the light novel so might write detailed spoilers from next week