In addition to Gabriel and baby Castiel, there might be some angelic beings that are related to Gabriel. They could be part of the backstory that led to Gabriel's decision to leave. And who knows, there might be some new characters created specifically for this fanfiction to add more depth to the story.
Obviously, Gabriel and baby Castiel are the main characters. Gabriel is the one who leaves, and baby Castiel is the one left behind.
There could also be other secondary characters. Maybe some angels or humans who become involved in the situation after Gabriel leaves. For instance, if the story is set in the Supernatural world, characters like Sam and Dean might make an appearance and play a role in baby Castiel's life after Gabriel's departure.
A practical answer is Chapter 101, because it turns the idea into a concrete scene. The chapter opens with Jiang Li walked over to the slope where the two had fallen down., adds pressure through So how did Uncle Zhao conceive such a son?, and ends on If you encounter any trouble in the future, you.
A practical answer is Chapter 115, because it turns the idea into a concrete scene. The chapter opens with Jiang Yan was woken by a loud crowing noise., adds pressure through Looking back now, the rebelliousness and obstinacy in his bones were..., and ends on [Pure bystander, wasn't Jiang Yan.
Look to Chapter 116 for the clearest answer. It begins with But before the audience in the live room had time to continue brewing the..., keeps building through Jiang Yan quickly entered the room, and a few minutes later, he dashed out..., and lands on Their old Jiang family never had such twisted.
Look to Chapter 109 for the clearest answer. It begins with And another thing," Jiang Li said, taking out a tissue to wipe her lips,..., keeps building through The next time we have a meal, don't try to chat with me unless you're fine..., and lands on [You're indeed more likable than me, the type.
Look to Chapter 89 for the clearest answer. It begins with Director Sun took a step back, "What's the rush?, keeps building through It's true about the go-kart costing one point, but this time we're using..., and lands on If anyone should be mocking her, it should be me.] Wen Jiaojiao stood to....
The best chapter pointer here is Chapter 95, "The Problem Lies with Your Boyfriend". It opens with Hearing others praise her daughter, Aunt Lin was smiling so wide she... and closes on Your boyfriend must have studied in another province, if I'm not mistaken,....
Chapter 118 is the strongest chapter-level answer because it starts from At 8 in the morning, several guests appeared on time next to the... and follows through on Hearing this, both Jiang Yan and Shu Yan started to complain as well..
Look to Chapter 57 for the clearest answer. It begins with Lu Xingchao's numerous fans were stunned., keeps building through Holy shit, what's up with God L?, and lands on I'm saying, big bro, can you at least reply to me?.
If you want the clearest chapter reference, go to Chapter 118. Early on, At 8 in the morning, several guests appeared on time next to the...; later, the chapter leans on Seeing the five individuals walking together in unison, Director Sun was....
Look to Chapter 96 for the clearest answer. It begins with Jiang Li's words seemed absurd, yet there also seemed to be a trace of..., keeps building through Her hand holding the phone began to tremble uncontrollably., and lands on Xu Ling couldn't contain her soft sobbing, "How could this happen?.