The answer to "should I continue this?" is always "It's up to you."

What do you get out of writing it?  What do you want to get out of writing it?  If you keep writing, how will you proceed?  If you scrap it, then what?  Is it more valuable to you to re-think your premise and discard what you have, or to practice the act of turning a concept into an actual written piece, even if you're dissatisfied with the product? (This dissatisfaction is inevitable, by the way.  That's the nature of any act of creation.  Learning to deal with it is important.)

These are questions that only you can answer.

That said, you're not going to get away with not developing a duelist.  Especially not if she beats Utena.  If you're going to pull this premise off at all, it'll be on the strength of how the characteristics of the OC duelist relate to existing characters and themes.  I maintain that (whether it's done to death or not) there is more to be said about the characters and scenario of SKU that an OC duelist could draw out, but it's a delicate balance.  One that I have, in the past, failed to maintain.

Kita said it best: it's up to you.  This could be the beginning of a kickass story or a blah one.  You have a nice hook, which is that your protagonist has no idea who e is or why e was dueling.  Personally, I like a good amnesia story, and this story drops us straight into the amnesia-driven conflict, which seems promising.  And I don't have sympathy for the viewpoint that you shouldn't write an OC duelist because everyone writes OC duelists.  But: do you know where you're going with it?  Do you know what your OC's motivations are?  Do you know what Anthy's motivations are?  There's nothing wrong, when you're writing for fun, with just dropping some characters in a situation and seeing what happens.  But as a general rule, before the story can be good and not just fun, you need to have an end in mind from the beginning.

IRG is happy to host fanfics that are fun, fanfics that are good, and fanfics that are horrible.    So it really is up to you.

I think my biggest problem with writing Utena fanfiction is that the story is already so... /told/. like... I don't feel like there's much I can do to explore in that world. but I want more of it, so I want to write fanfics

My intention with this one was to go into how sex with anthy probably wouldn't be all that awesome. Like... I was going to have it be all 'she makes you want it, but you know you shouldn't' and it was gonna be tense and stuff, but the context is hard to come up with, because to go through the gamut of feelings i'm thinking of, you have to know Anthy's position. So who better than a fan of the show who is swooped into the series for some reason

I'm thinking maybe it's to get utena to regain her conviction to fight for anthy? maybe?

I actually think a self-insert character could work here as well.  But if the point is sex with Anthy not being much fun, I wouldn't start the story with the duel against Utena, because if a character beats Utena in Chapter 1 then that's what the story is about.  It's not that your SI can't beat Utena, it's just that that's probably not where you want your reader's attention to be.  I would start the story after the duel, and have Utena be only a distant presence in the story -- unless Utena is an important part of the reason why sex with Anthy isn't much fun.  But I am no authority on good writing, so take my advice with a grain of salt.  (Except the advice about taking my advice with a grain of salt.  That advice you should take seriously.  This advice as well.)

I think the potential to take the premise of this story to new and exciting places is well within the realm of possibility, and you should continue. But as others have said before me it's up to you. As a writer there are two pieces of advice I want to leave you with. They are quotes from writers far greater than I can hope to be, but I live by them, and the lesson in both is very much the same.

"Sit very still and ask yourself, as a reader, what piece of writing in all the world Buddy Glass would most like to read if he had his heart's choice. The next step is terrible, but so simple I can hardly beleive it as I write it. You just sit down shamelessly and write the thing yourself. I won't even underline that... It's too important to be underlined."- Seymour from Seymour: An Introduction by J.D. Salinger

"The only reason to write is to write for love. Write for passion. If you have the privilege of being able to write, then don't do it for any other reason." - Stephen Sondheim

Always write the story you want to read, the story you want to tell because you love it. Don't do it for the approval of the masses. And share it with others even if you think it stinks. Because, if you've written your heart out then your story will resonate with someone. But, more importantly, even if the someone the story resonates is just yourself you've achieved something.

Alithea wrote:

Always write the story you want to read, the story you want to tell because you love it. Don't do it for the approval of the masses. And share it with others even if you think it stinks. Because, if you've written your heart out then your story will resonate with someone. But, more importantly, even if the someone the story resonates is just yourself you've achieved something.

I totally agree with the sentiment that you should write what, figuratively, gets your rocks off. Other people will write exactly what they want. As for sharing? Well as an SKU fan and a site administrator I absolutely love when people share. As an incredibly selfish writer of horrifying purple explicitly self-inserted Literotica style shit? Uh...some things you keep to yourself.

Either way, the point is that you enjoy what you're writing.