Akira, Fate/stay night: Unlimited Blade Works 2nd Season Recommendations
Both animes are in a pre / post-apocalyptic era.
Akira: it is the third world war between 1988
Fate: this is the 4th Holy Grail War
and each has ravaged the city in which the main characters live. (Respectively Fuyuki City and Tokyo for Fate and Akira)
I also think the movie Akira will help the fans of Fate to better understand the views of Gilgamesh on humanity.
The universe is more fantasy / magic in the modern world (2000s) in Fate / Stay Night. Akira takes place in a dystopian futuristic universe. (2019)