You're joking, right? You must be joking. Yana Toboso has made a confessional for Grelle. There is canon evidence, written by Toboso in which Grelle answers our questions. I can easily link it to you. If you are going to disregard that and pretend that Toboso hasn't explicitly (and implicity countless times) that Grelle is a transgender woman, you are transphobic.
Hello! No, I’m not joking at all and I’m wondering if you were suggesting you link me to my own post, which you liked earlier? Yes, I’m very aware of Grell’s Confessional and that is why I posted it in both English and the original Japanese for people to look at. I also, however, included the pages that preceded the interview in the Character Guide in that post.
On those pages, and on her blog, Yana Toboso uses the pronoun kare. This is from the Japanese word kareshi, which means boyfriend, and, while it can be neutral, it generally translates to “he” in English. She uses this consistently, contradicting Grell’s personal pronoun use. She and Grell also refer to Grell as an okama, a word usually reserved for effeminate gay men and crossdressers, in two posts [alternate links]on her blog. Finally, if we include OVAs as canon, Grell says in Part 2 of the Ciel in Wonderland OVA that [they] are “already constrained because [they are] a ‘halfway’ existence that doesn’t know if it is a man or a woman,” which suggests a certainly non-cisgender identity, but very possibly a genderqueer one.
I will never claim that Grell is not trans in some respect because I absolutely believe [they] very well may be. However, taking the common misconceptions about transgender and gay people in Japan (which I’ve discussed most in-depth here and here) into consideration along with Yana Toboso’s choices in pronouns and terms for Grell - which suggest she may intend Grell to be interpreted as a flamboyant man, crossdresser, or non-binary person - I believe that we simply cannot say with absolute certainty what Grell’s gender is right now.
If you want to disregard those parts of canon, that’s fine. It doesn’t bother me in the least. But I will continue valuing the author and creator’s language as equal or more important than the character’s because only she knows, without a doubt, what Grell’s gender truly is. Her pronoun choice is awesome and so is yours.