So, my old fixation on the Sage Witch is back now. and I have a new what if! idea ;)
Another universe, Another Sage Witch..... where their universe is being torn apart (let's say by a temporal rift) and they need to go back in time to get the Tesseract to seal the tear. y/n, sam, and Bucky go back to the 1940, just before World War 2 to get the Tesseract.
Bucky has a second glimpse of his time if HYDRA hadn't taken him in and he reflects back on the memories he lost to HYDRA.
And they run into Young Sargeant Bucky Barnes;) who flirts with y/n on instinct and then agrees to help them.
A little angst, a little fluff.... and then they return to their time in the future, save their universe (Loki will be making an appearance) and all is good.
y/n returns to 1940 to return the tesseract and has a cute farewell moment with younger Bucky.
The end.
I was re-watching The Adam project and i couldn't get this idea out of my head.. so here we are.....