Welcome, Pazolith!
So, in general, there is a bit of an issue with injecting stuff into Pangya.
In general, following things have to be noted:
- New items and item models can be added to the game, these are purely dynamic
- New characters can’t be added (references are hardcoded in the game)
- New courses can’t be added (references are hardcoded in the game)
You can, however, replace a course or character, but I don’t think people have made a lot of advancements with that yet.
Anyway, back to your specific question about injecting models.
Models in Pangya are called “puppets”, they have their own file format. I partly have it described here:
There are a few tools to work with models:
io_scene_mpet (imports mpet files into Blender):
This set of PAK tools includes a converter to metaseqoia model files:
An importer for Pangya models for 3DSMax:
http://hsreina.shadosoft-tm.com/#post_139
Currently, most of the tools seems to be one-way solutions to export the models and not import them back into the game.
Not to promise anything, but once my PET parsing library is a bit more advanced, I (or someone else) could use it to write importers and exporters for specific model file formats. At the moment that landscape is a bit barren tho.
In the meantime, start modeling your ideas anyway, and maybe in reasonable time, there might be the tools available! 