I don't have any new images to post so I'll contribute with fanficrecs focused on Nagisa.
https://www.fanfiction.net/s/10835760/1/Country-of-SweetsPost-rebellion. Well written, with a cute chapter dedicated to our cheese lady. There're hints that it will become darker later on though.
https://www.fanfiction.net/s/9966378/1/Magia-Pacem-Bellum-Terrarum-Those-FallenIt's a sequel. Post-rebellion. Epic plot with lots of original magical girls. Nagisa is more mature and serious in this one. Author seeks the best quality in writing, so the story received a revision recently.
https://www.fanfiction.net/s/9939603/1/More-Than-a-WishSlow updates. It's a "if Madoka made that wish." scenario. Nagisa is introduced later on in the story. Fluffy!
https://www.fanfiction.net/s/11437707/1/A-Curse-Between-UsPost-rebellion. Slow updates. Nagisa lives with relatives in this story, but she's still Mami's sidekick during patrols in the city. A good mix of action, drama and SoL moments.
https://www.fanfiction.net/s/10034329/1/CheesecakeJust the best "Mami saves Nagisa from becoming a witch in the original series" scenario. Deadfic and better this way. Let they frozen in happiness before Walpurgisnacht appears.
https://www.fanfiction.net/s/11022529/1/DisconnectionPost-rebellion. HomuNagi and it's not crack! Tons of angst. Kyoko is the very best. "If she could not solve a problem, at least could leave it cute!"
https://www.fanfiction.net/s/11228999/1/FargoPost-rebellion. Complete. Epic story with rich vocabulary and alot of OCs. Nagisa is a cheese junk, also older, but she'll only really appear later in the story and it's a long read. Loads of suffering and violence, deserved a M rating.
https://www.fanfiction.net/s/8983147/1/Gunners-HighIt's a sequel. Complete. M rating story with Nagisa? Yes, we sure have. She's introduced later, since this fic started before Rebellion movie. Spicy ending, but cute nonetheless.