#undertale!mettaton

Undertale!Muffet - You might actually unlock Muffet's softer side. Yes, despite her seemingly violent and greedy outer shell, she actually is a very gentle soul on the inside -- she is merely doing what she needs to to survive. Anyone who would be even remotely sympathetic for spiders would earn Muffet's trust, but to be empathetic is on a whole different level. It wouldn't be unreasonable to assume someone like this would make a donation or few to Muffet's bake sale, despite the prices, and a repeat customer who doesn't seem upset after spending their money is enough to leave her intrigued.

Undertale!Mettaton - You would remind him of Blooky, all things considered, although empathy is not necessarily wholly negative like most of Blooky's emotes tend to be. Mettaton would honestly find great interest in you and he'd actually more often than not find himself opening up around you without even realizing. Despite being so loud and proud on stage, Mettaton would be rather gentle and quiet around you, and probably be rather careful of your sensative boundaries without even realizing it.

More commissions! The final two from this round of commissions~!

Mettaton with their BF commissioned by @stage-one-happiness-froth

The Old Man commissioned by @firedrakegirl

Overall, I can't see any of them doing anything necessarily negative in regards to their S/O using new pronouns, but I do think that they would have different levels and kinds of support.

Underfell!Papyrus - His support would be immediate and aggressive. Not aggressive to you, but rather to other people. Edge is gonna be that type of person who the moment someone uses the wrong pronouns, he'll immediately correct them. If this ends up being something you're not a fan of for one reason or another, he'd be willing to talk it out and calm down, but it would take some adjustment. If someone consistently uses your old/otherwise wrong pronouns though, he's throwing hands. And by throwing hands I mean mercilessly giving them a strong talking to.

Swapfell!Papyrus - Rus is a lot more laid back than Edge, so while he will be supportive, he's not gonna go jumping on anyone that screws up. Especially since this is an add-on and not full replacement of pronouns, he'll be pretty lax with it so long as you are. He'll probably use they/them in reference to you when talking to other people every once in a while to subtly hint your new pronouns. If someone tries to complain to either of you about your choice to use they/them though, he'll have to really resist his urge to beat the person into a pulp.

Undertale!Mettaton - This man will just short of begin advertising to the world your new pronouns in excitement. Which might be great, or also a bit too much. He can try to tone it down if necessary, but that will be such a struggle for him given how Mettaton can't keep anything a secret. Really, if there's anyone he's not supposed to declare this to, it's best to remind him of that if you ever go talk to them together. Perhaps not too often, or he might get annoyed himself by too many reminders. But just so he doesn't blow your cover. And if that's not an issue for you at all -- even better. You'll be a perfect fit for Mettaton's loud and proud personality.

Undertale!Gaster - He doesn’t really mind. Gaster’s pretty laid-back with most things and he’s willing to be patient with someone who has difficulty understanding emotions. They are a difficult concept after all, so no need to treat it with such seriousness. He’ll be pretty chill about the whole thing and really won’t worry one way or another. Though, he’s not one for serious conversation, so don’t expect him to sit down and have a wholly genuine, joke-free conversation about this pretty much ever.

Undertale!Chara - Possibly shocking, possibly not -- Chara isn’t a fan of this. While not exactly someone empathtic themself, they do kind of expect other people do be so, or at least have some sort of ability to recognize Chara’s desires without them having to really say a whole lot. Chara’s a very emotional person with very little impulse control, so frankly, it might be a bit between someone who can’t communicate their emotions well and someone who can’t understand them very well.

Undertale!Asriel - Asriel understands you completely. He couldn’t feel any emotions as Flowey, much less even so much as sympathize with anyone else. He’ll be the most proactive of this collection to try and help you do everything you’d like to do. With his own desire to better himself as a person, he would love to do a lot of good deeds and other various positive impacts on others’ lives. The potential biggest issue is that Asriel himself is a very emotional person, but he’s also used to being around people who don’t necessarily recognize or reciprocate that.

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Papyrus and Sans dont mind winter since Snowdin was super cold, but when it's any other season they're way too hot and can't handle it. Summer is notably worse for Papyrus because the heat is so bad he can't get any work done, which makes him especially annoyed. Spring is notoriously bad for Sans because it's more rainy, and not only does it mean his slippers would get absolutely soaked which inevitably means wet socks, but he also can't stand thunderstorms.

Undyne physically doesn't do well in most weather conditions unless it's humid or raining, but she forces herself to work normally regardless. When it's hot and dry, she works herself way too hard and it's Alphys who has to make her take a break. Undyne tries to combat the dryness by keeping full water bottles on herself at all times, but even still she still can get sick if not careful. Alphys practically has to force her to stay inside during hot, dry days in the summer.

Alphys doesn't mind most conditions, but prefers summer the most. Summer is nothing compared to the heat of Hotland, but it's comfortable, so she likes it the best. However, Alphys hates snow, so she usually stays inside during winter w hot chocolate and anime binge watching.

Mettaton, Mad Mew Mew, and Napstablook are unaffected by the weather due to being ghosts. Mettaton's body temperature, however, can't get too hot or cold or he'll crash until it goes back to normal state -- he usually operates at about 35°C (95°F), but if he gets below 20°C (68°F) or above 60°C (140°F) that's when his body is in critical condition. Mew Mew's body, being a doll, isn't affected by weather at all. Muffet lives in a similar condition as Mew Mew.

Grillby and any other elementals will remain the same temperature no matter the season. However, Grillby will be in extreme pain if he walks outside in the rain.