Crowley & Aziraphale

For Aziraphale, he has just given Adam his flaming sword so that he and Eve can survive out in the wilderness and then shields Crowley (his assigned enemy) from the rain with his wings, all the while having a friendly chat. This establishes that not only is he predisposed to be an affable Nice Guy, but he is like this in a manner that defies his duties as a member of Heaven's armies (since giving someone else his flaming sword is a massive no-no) and as an enemy of demon-kind (as his friendly conversation with Crowley would indicate). For Crowley, he has just finished tempting Eve with the apple, leading to her becoming pregnant and she and Adam leaving the garden. Crowley (then named Crawley) watches them leave the garden alongside Aziraphale, and remarks how knowing the difference between good and evil (which is what eating the apple granted Adam and Eve) does not seem as big a deal as everyone claims it to be. When Aziraphale points out that Crowley wanting it to happen makes it evil by design, Crowley waves it off as just wanting to "make some trouble," then going on to poke holes in the setting (like how the location of the tree was just inviting disobedience). This establishes that while Crowley does take some delight in the strife he sows, it is more of a job to him and he is willing to question the ethics of what they do (unlike other angels and demons, who are fully committed to objective morality).

Example of:
Establishing Character Moment