In Madoka Magica, when a Puella Magi contracts with Kyubey, they make a wish. This wish will shape them as a magical girl, defining their abilities. Homura's wish pertained to time, and as a result, she's got time magic. In Subnautica, she has retained her ability to stop time. Once this ability has been activated, anything that Homura is not in direct contact with will be frozen, unable to move and unaware of this. Essentially, your character would most likely not know time has stopped. It'll seem as though nothing will have happened, unless Homura has done something, like move or uh, shoot them. (Don't worry, she isn't guaranteed to do this, and I'd work it out with you first!)
While I won't be skirting around her time magic in open posts, I would like to try and make sure that no one gets involved with Homura's magic unless they want to be. As such, if you could fill out the form below, that would be cool!
Additionally, while Madoka Magica spoilers might be a little hard to avoid elsewhere, I'd like to try and keep them to a minimum for anyone who doesn't want to be spoiled. There's an option here to opt out of spoilers, so please let me know how you feel about those, too!
And finally, for characters with time related abilities: I am totally cool with Homura's abilities not affecting your character. Let me know if you do or do not want this to be a thing, please!
While you're here, feel free to check out Homura's character specific permissions
, too, if you're curious about those.