Hey @Koro,
Event Categories are a separate taxonomy and will not show up next to “normal” Categories unless you were to do some extensive code customization.
I’m sorry if I’m misunderstanding your question at all! If you think I am, you can share screenshots of the issue to help clarify things. You can do so by uploading the screenshots to Imgur.com, Flickr.com, CloudUp.com, or any similar image-hosting site; then just share the links to those images here and I’ll take a look.
Thank you!
George