I've heard a few female characters use the Ore pronoun (such as Charlotte Linlin from One Piece or Veruschka from Nights of Azure 2: Bride of the New Moon). Ore-sama is something I've only ever heard from male characters though.
"I squirm, I struggle, ergo I am. Faced with death, I am finally, truly alive."Just use ware, it's the most gender-neutral thing. That said, there are no "arrogant-sounding" pronouns that are at the same time known commonly enough that someone who does not know Japanese would be able to note them as sounding anything but foreign to them, so I see that particular sub-plot of yours as contrived. Think about that for a moment.
I write a Bokukko (not that I know enough Japanese to show it) whom I could imagine using "ore-san" once or twice.... Not quite the same level of arrogance that you seem to be shooting for, but I thought I'd throw my two cents in....

I'm working on a story where the protagonist is a Japanese woman. She's a genuinely noble and heroic figure, but also one who's extremely arrogant and narcissistic. There's a scene where she has a conversation with someone in Japanese. Her friend listening to the conversation doesn't understand, but picks up a few key words. The friend notices the protagonist use an extremely arrogant pronoun when referring to herself. My question is, which pronoun should I use?
I looked at the list for Japanese Pronouns and found two that might fit: ore-sama and wagahai. However, when I looked these two up, I found that they were exclusively male pronouns. Is there a female equivalent to these? Or should I just use one of these pronouns anyway?