these lines we use to represent our characters are just lines after all. do w/e you want with 'em imo

Just like in real life, there is no "right" or "wrong" way to look when you're trans.

However, if the FC is confirmed trans and or gender non-conforming in their series, it'd be iffy to say they're cis when you use them for your character. Okay so, May Marigold from RWBY is a trans woman. If I saw someone using May as their character's FC, but the character was a cis male, hooooo buddy, would we be having problems. You know what I mean?

I have seen what you've described before though, with Ciel from Black Butler. And at the time, I thought that was such a cool idea! And it was the same idea, the FC just fit the character better, and there was none of this "oooh look it's a boy FC used for a girl wowie zowie". Instead it was just "this girl is doing her thing beep boop bop". Which, idk, imo, as it should be? But I say that as a trans person who's just trying to vibe through life without everyone making a big ol fuss about determining my gender lol.

tl;dr you're fine, just be cool and respectful about it!

I mean, like the guy above me said, there's no "right" or "wrong" way to look. My personal opinion is that Face claims are just Face claims. It's when a roleplayer picks a drawing or image of someone to use as a physical description of your character, and since it's your character, I think there's no need for you to contemplate who you use. It matters not if your FC character is confirmed man, women, trans man, trans women or non binary person. All that matters is that character looks like how you envision your OC to look. There's no need to feel like you have to justify yourself. 

tl;dr - Your FC is your FC. It doesn't matter who or what your FC is in their respective origin, because your not writing about that character. Your writing about your character. You do you.

I feel like it's advisable to use trans FCs where possible, but the sad reality is just that there aren't a lot of trans FCs. The only solutions are to use cis FCs, or just not play trans OCs once the handful of actual trans FCs are taken, real life or otherwise. So unless you just don't use a FC, you're kinda stuck!

Do whatever you want tbh. At the end of the day you're just using some anime character to represent your OC on the internet. Who that FC was within there fandom shouldn't/doesn't matter. I think we get a little top caught up in the political correctness of it all. Just have fun, that's what this whole roleplaying thing is all about.

I agree with the rest of peeps here. There is no wrong answer - admittedly, trans people can range pretty much anywhere in 'obviously trans' to 'oh wait, they're trans?'. It just depends on what you'd like to go with.

If you're going "wait, that's a male?" you're probably safe to use them for a female ... trans or otherwise.

that's edging into "trap" territory, and i am begging everyone reading this, from the bottom of my little trans heart, to not do this.

the whole "surprise that's acTuAlLy a girl/boy" will never be funny, will never not be transphobic, and will not be a good look.

if your character is female but looks masculine because of the FC? own it. if your character is male but looks feminine because of the FC? own it. if your character is neither, but looks either or because of the FC? own it. just own up that they're not "traditionally" anything, or just admit outright that they're trans! and that's okay!!

but please please please don't do it as a gimmick or a joke. I am not claiming anyone else (especially not you Em, I'm not saying you will do this, but you made a very good launching point for this subject). Like I said before in my earlier reply, use whatever FC. Make your character cis, or trans, you do you.

But do NOT do it as a "joke" that is transphobic in nature. that's all I really wanted to add.

Not to mini-mod, but I'm not sure how you came to this conclusion, since, as a whole, this is an advice thread about being respectful for meta reasons. (And since this was moved to Advice lol)

I have seen some (not all; not many) trans people tentatively accept the "trap" archetype, or at least define it as separate from "being trans," and could totally see a person labeling themselves as one whether in some act of reclamation or even for negative reasons (self-deprecation, mockery). But that doesn't have much to do with face claims. You could specifically use a character of the archetype as your face but I've seen people use the pink-haired guy from Fate for a cis man, enby, and trans man before on separate occasions which... I wouldn't do, because I think that character's tacky, but it reinforces what a lot of people are saying in this thread, anyway.