Out of 5 - Results (9 votes)
https://tvtropes.org/pmwiki/pmwiki.php/Main/FireForgedFriends
Whether hostile to each other, indifferent, or strangers, different groups must fight on the same side. All the way up to an Enemy Mine situation. Afterwards, they are no longer hostile and perhaps even actual friends.
Examples:
Emperor's New Groove -
Kuzco and Pacha
Avatar: The Last Airbender -
Aang and Zuko
Lord of the Rings -
Gimli and Legolas
This is an easy 5 for me, I absolutely love this trope
http://steamcommunity.com/id/gamerfanfan/wishlist
Oops, we trained a monkey to be a fascist!