Key will turn into a human later in the story, or at least take on a human form
- Key struggles with his past as an Incubator Drone, and despite having gained empathy and individuality, is still full of self-loathing for the harm he's caused. Deep down, he wishes that he can be human both so he can (from his perspective) fully integrate with his friends and live a happy life where he no longer has to cause problems for people. Unexpected circumstances will grant Key's wish as he takes on the form of a white-haired human boy around Nagisa's age, which allows him to fully enjoy the pleasantries of human life, such as eating food without having to worry about throwing up. The story will end with Key either fully becoming human or at least gain the ability to switch between the forms of a human and an Incubator.
Homura will meet the version of herself that became a Devil and will be tempted to accept her offer to trap Madoka and her friends in the same Lotus-Eater Machine the other Homura created in her timeline.
- Homura will meet Devil Homura who explains how she became to be and offers her a chance to finally give Madoka a safe and happy paradise while also making the Incubator race suffer for their actions. In a scene extremely similar to Buzz Lightyear's confrontation with Zurg, aka Buzz's Alternate Self, Homura will come to realize this paradise isn't really worth betraying Madoka's wishes, remembering Ryoko Tanbo chose to allow her friend to pass on peacefully and coming to understand that there's a big difference between protecting Madoka and trapping her. Not to mention, Devil Homura also intends to torture Key just for being an Incubator, whereas Homura has already formed a strong bond with the Rogue Drone to the point she is just as protective of Key as she is to Madoka.
Homura's backstory will be revealed to the group by accident
- Madoka, Key, and everyone else will accidentally wander into Homura's memories during a pivotal moment, revealing to them the kind of person Homura used to be and how she became the person she is.
Homura and Key's Fire-Forged Friendship will begin after one of them saves the other and both end up comforting each other during a heart-to-heart moment.
- Homura will eventually realize just how much Key means to her after coming to understand just how much he's helped her and Madoka during their times of strife, eventually leading her to see Key as a close friend or little brother figure and become just as protective of him as she is to Madoka.
Key will fully become human at the end of the story.
- Once the matter of Walpurgisnact and the Witches have been dealt with, Key's innermost wish to become human will be granted, and he'll also end up becoming Homura's adopted little brother.
- Alternatively, Key will pull a Heroic Sacrifice, but he'll be revived as a human being without any of his memories of being an Incubator. Despite not being able to remember his previous life, Key's kindness and empathy still remain with him, and he'll subconsciously feel attached to Homura, Madoka, and all their friends. Having grown to care for Key as a friend and trusted partner, Homura will take him in as a foster brother and actually become a Cool Big Sis to him, albeit while keeping his past as an Incubator a secret. She'll take Key with her to visit their friends, with the now human Key resuming his friendship with the girls.
Key will reunite with the three girls that caused him to gain emotions and individuality.
- Their reunion will help Key when he suffers a Heroic BSoD, with the girl whose Soul Gem he purified revealing that she never hated Key and makes it clear she still cares for him. This will lead Key to cry when he realizes that girl he manipulated still loved him and make him realize he truly has done a lot of good, thus allowing him to keep moving forward.
