Congratulations! Due to an anonymous cosmic being getting extremely drunk, you have been placed in charge of an omniversal temp agency that lets you assign fictional characters to be in charge of other fictional characters!
The catch is, while their involuntary clients will definitely obey the instructions they are given by their new supervisor(s), not only must the temp not deliberately interfere with their new subordinates' actual goals, they are only in charge of one specific aspect of their lives.
For example, if Ochako Uraraka, AKA: Uravity, of My Hero Academia is put in charge of the X-Men's code names, they will most likely end up going into combat referring to one another but things like "Jimverine," "Scottclops," and "Jeanix." If Tomoyo Daidouji (Card Captor Sakura) is put in charge of Iron Man's aesthetics, then his armor will remain mostly as effective as ever, but now they are all covered in frills and a tendency towards pastel paint jobs. Similarly, if the kayfabe version of Duane "The Rock" Johnson is put in charge of Sailor Moon's (either the entire team's or just their leader's) speeches, well, I imagine that her implicit death threats will suddenly become a lot more explicit and aggressive.
So, go forth, and create the most entertaining and/or effective employment opportunities!