I kind of like that, good stuff.
Her Eldritch Horror "true form"?
Huh, would not have expected that from Mystia. (Especially since I have it in my head that she's the 2hu equivalent of Moh Shuvuu from Megaten.) Got more details/screencaps or something?
This one's also a bit surprising to me, she's one of the few 2hus I don't generally get along with or like.
Mostly this is because of the things she does in the official manga stuff, things that netted her the nickname of "Tewi the shit" or "Tewi a shit" among a few of the community , like the whole
"selling rabbits to villagers in the hopes they experience enough suffering & get abandoned and become rabbit youkai minions during the winter" kinds of things. She's normally extremely selfish and self-serving. That isn't even getting into the Reisen bullying stuff.
There's more stuff like that but yeah, certainly an interesting side shared here of her perspective of why she does things at least and actually makes me empathize a bit.