So I finally got to sort through the one folder in the new Tera Leak that has S/V production documents. The only direct Kiki mentions I could find so far (for what it's worth, I doubt there's anything more) are from these spread sheets, which contain play tester comments about the DLCs' story and game play. From a quick machine translation check, it sounds like they didn't quite get Kiki's character. I wonder if anything got changed in the final versions...
https://files.catbox.moe/vd4ls1.zipPlease let me know if the download link doesn't work, Catbox is acting up haha. Sorry for no Kiki pic, I will make up for it!
