This is the first in a line of fanfiction crossovers between the Doctor Who Universe and the Marvel Cinematic Universe. and just so we can get this out of the way so we can avoid debates in the comments, in this story, the Doctor and the Avengers don't actually fight. I just thought Vs. sounded better than And.
Synopsis: The Doctor and what remains of the avengers must unite to defend the planet from an invasion of Daleks, Cybermen and an enemy that Earth's Mightiest Heroes believed was long gone.
To read the story, go here https://www.fanfiction.net/s/10968644/1/Doctor-Who-Vs-The-Avengers-Pt-1