Just that the japanese doesn't use Kris BECAUSE THE DRAGON DOESN'T HAVE A NAME YET YOU DONKEY
I fucking can't
You have absolutely no clue about grammar and you don't even understand the story but "hur dur singular they bad"
Look, I'll give this a pass because Kris is non-human, but if the dragons ever become human then you're gonna have a problem. If they become human, then their characteristics will determine which to use, because pronouns in languages are descriptive—if it looks like a guy then it's "he", if it looks like a girl then it's "she".
And I could say the same to you, you have no clue about grammar as someone translating another culture's work. You're supposed to show us the author's work, not your own crap. And for your information, I have studied Linguistics
and Japanese. I'm aware of Descriptivism and Linguistic Relativism. Hence I'm not denying some people use it, but instead I'm stressing to be as neutral as possible. It's not an accepted form for most English speakers and intentionally insisting on using it almost puts you on the same shit level as the translator of Shinozaki-kun no Mente Jijou that keeps insisting the bunny girl is Non-binary when in-raw characters either refer to her as a girl or omit it because Japanese drops them. It's understood from context that she's a girl, don't make it weird and shit.
Most neutrally:
As bones, just refer to "it".
"The divine dragon is long dead, we have its bones."
Once revived and named as Kris, use "Kris". It's understood from context that the character being referred to is Kris, even if the original Japanese omits the referrent noun.
I probably understand grammar better than you do. Singular they isn't any more accurate because the Japanese wouldn't have it either. Japanese would use either use the name or omitted reference, and very rarely 彼/彼女. Otherwise Japanese prefers noun phrase constructions.