Thanks for the kind words! ^__^
obj_battlecontrol is the heart of the engine, I think its state machine contains almost half the code in the entire engine... but it's not quite enough to import it alone since it also communicates with the menus, the monster/move/party databases, and battle monsters and effects are their own objects.
There's a lot of dependencies between the different things in the engine, but I think something like this would be a good starting point if you want the entire battle system:
- Everything in the "Battle" and "Menu" objects folders
- The "Menu" objects have dependencies to the Menu Events, UI, and Drawing script folders
- The "Battle" objects have dependencies to the Battle, Data Mangling and Effects script folders
- There's a lot of misc dependencies to the "Maths n String Handling" scripts (in particular tsprintf is used everywhere)
Importing all of these would be a good starting point, and then test-playing to see if you get any "unknown function was called" errors - then you can make a judgment call if you'd want to import that script or replace the call with one of your existing ones (like the sound effect / music scripts - you probably have your own setup for that if you're partway through a large project).
Good luck! Feel free to ask any questions you're stuck on here, I try to check my Itchio notifications at least once per day.