Leona's lore. Wow, really. Really.
Why does she want to kill Diana even before the Elders's order? That's NOT the Leona we know. Everything else is fine, including the fact that she came to value life after a personal evolution, not just always having been like that - but why would she want to kill as heretic someone who clearly found something actually existing? Why wouldn't she want to know what it's about first, and then dissuade if there's a problem, before even thinking about conflict?