He was born in a family with a long line of medical professions. His parents Doctor Jacob Cheng and Doctor Lina Cheng, were a neurologist and a Hematologist respectively and his grandfather was an acupuncturist while his grandmother was a sort of chiropractor. With this, great expectations were put on the newborn as they expected him to follow in their leads. Even his adopted white older sister Jane was thought to go into the medical field because of the family. She was three years older than him.
As an infant many thought him to be queer or abnormal since he didn’t act his age. He never cried, never made “baby sounds”, never played with toys or anything really, and seemed only interested in reading books. Not books meant for his age, but middle to high school level books.
When he could talk he didn’t imitate what his parents or older sister said, instead he would ask them about their day or what they did at school or work.
Only his parents weren’t put off by his actions as they thought of him as a genius and wanted him to succeed in medical school and become a doctor just as they expected. Jane didn’t mind it much and actually enjoyed talking to him as she too liked the idea of having a genius little brother.
All of them felt proud of him and loved to boast about their two year old was able to potty train himself as well as read and write.
Others, however, were not as accepting. Visitors and non-intimate family members avoided him. To them he seemed too smart for his own good. His growth was abnormal but so was his imaginary friend.
Usually they were just figments of the child’s imagination, but something about Ouroboros seemed off.
His uncle Jun onced asked what Ouroboros thought of Tristan. Jun expected a childish response like “Oh hes awsome!!” or “He's the coolest dude ever!!!”.
However, “Ouroboros finds me to be quite the suitable vessel to live in and I find it to be a nice roommate to share this body with,” was his reply.
He then went on to say with a eerie grin “Listening to it made me smart, Boros doesn’t like to be ignored so I do as it says.”
Jun’s conversation with the baby drew up talk about evil spirits and demons from the older people but soon it was thrown under the rug so to speak as whatever Ouroboros was did make Tristan smart. Maybe it wasn’t so bad they thought.
When his little brother Zhang was born three years later, the two were inseparable. Zhang’s weaker than normal body meant that he always needed extra care compared to his siblings. Tristan installed himself as Zhang’s caretaker and they did nearly everything together. Jane wasn’t as close but she too deeply cared about her sickly baby brother and was usually the one who carried baby Zhang everywhere. He didn’t care about his lack of friends, to him all he needed was his family.
His highschool years were not especially eventful.
Occasionally Jane would sneak into his room at night and slip a few suggestive magazines here and there, Zhang would also sneak into his room but he would sleep inside the unused futon located in Tristan’s closet claiming it “puts him at ease being near big brother”, Ouroboros would mentally force him to excessive physical training for unknown reasons, and he would learn acupuncture and anatomy from his mother and father whenever he could(which delighted them as it showed initiative towards a career in the medical field).
His teachers enjoyed him as he was less troublesome than most students, but his stoic, calculating nature made many of them anxious as they could never even guess what went on his mind.
His habit of talking to himself or Ouroboros only made things worse since it made his classmates believe him to be insane. Staying near him, they believed, would make them insane as well since he was giving off a weird aura of someone who could do that.
Bullies who attempted to extort money from him almost always end up with a broken arm or leg and maybe a few missing teeth. Where he learned how to fight no one knew for sure, but some say his “friend” would take over and do the fighting for him. Regardless, no one at school wanted anything to do with the boy afterwards.
Overall, aside from Ouroboro’s influence, Tristan lived a normal life as a loner. If no bothered him he wouldn’t bother them; that's just how things were for him.