It might be a stupid idea but I had to get it out in the open.
Castiel gets rescued/resurrected, from the empty, by Jack and sent to Earth. It’s in the future, so earth might be a little different. He has his full angel powers back, including his wings.
Castiel wants to visit heaven, but for some unknown reason, he can’t.
Castiel has a new charge, a female Nephilim, of an archangel. Idk which archangel is the father. For some reason I have Michael in mind, but it would be logical that the father was Gabriel.
This female Nephilim was born around the same time as the Winchesters. Chuck however, kept her to himself and didn’t want her caught up with the Winchesters. It’s undecided if the Nephilim has been in contact with Chuck since Amara first appeared, that’s if Chuck is still alive. They had a complex relationship. She has been alone roaming Earth, for awhile now.
The Nephilim is also a scientist, so if she is going to be in contact with Chuck, it will be because he retained some knowledge of the universe. She always saw God as a scientist.
Gabriel might be alive, but idk if I want him as her father or love interest. Castiel will eventually be her love interest, that’s for sure.
I have it in my head, that the adventures take place in the desert. Not an American one. The female Nephilim is not American. Idk where she is from yet, Europe, Middle East, Australia, South America. It’s one of those deserts, in that part of the world, but she has spent time in America.
She also loves driving a lot. Castiel finds her difficult, especially when arguing in the car. She reminds him of Dean. He is still apprehensive about her. She may be in interested in him, he doesn’t know how he feels about that.
Castiel is in awe at the state of the Earth and current affairs. If it’s in better or worse condition, is undecided.
Jack and Amara are dealing with the empty, so there won’t be much intervention.
How I see it is, Chuck deliberately made the female Nephilim. He made draft after draft, to perfect her. Chuck, made the female Nephilim but let Jack happen. Chuck was apprehensive about the two Nephilim, meeting. It’s unclear why he made a female Nephilim or why he let Jack be born.