I read the most hilarious Boku no Hero Academia fanfic about a year or so ago, about the class finding out how horrible Endeavor is and they make it their mission to make his life miserable.
There's been tons of fanfics about this subject, but there's one scene that particularly sticks out in my mind and I can't find it which fanfic it was from.
The story was on archive of our own and had a few chapters comprising of snippets of different scenarios. In one chapter it's time for hero internships and instead of Shouto going to his father's agency, they send Momo instead who pretends to be Shouto...but in a super obvious and hilarious way.
She smears red makeup (I think it was lipstick) over half of her face to mimic his scar and wears a mop or some sort of stringy wig on her head, dyed to be his colors. Then to represent Shouto's fire and ice abilities, I believe she holds ice in one hand and a lighter in the other.
She goes on in a deadpan way the whole time, reaffirming that she is Shouto and eventually his agency goes along with it, lot's of laughter gets aimed at Endeavor. She ends up doing this for the whole week.
I'd like to find this and re-read it so I can die laughing again.