I know this is a big ask but i'd love to see a gallery mode/ custom battle mode where you could have battles with a mixture of enemies, and apply different status effects. I had this idea while Nel was fighting in Celica's body, but it i could never get a grapple animation to last since her chance of escaping while struggling is so damn high "-_-
Also i'm yet to experience this "petrification" status effect mentioned, does anyone know where i can see this?
Some things which are mentioned in the library books don't seem to be accessible in the current version. Like the darkness and light elements, along with the petrification status that you mentioned. There's also confusion and charmed which have not been implemented in any battle yet.
There's a build for patrons which lets you play as the enemies and Evie while she's an ally. If you max out your Allure trait as much as possible then Nel will try less to break free from struggles. Grapples mostly break in one struggle with her because letting her possess Celica increases her Luck trait which increases chances of breaking free of grapples.