I would prefer to have Front Sprite with normal pallet and backsprite with shiny pallet, as 2 separate .png files for each species (or forme).
I didn't realise that Gracidea wasn't a hold item until after i'd made the video. Just for accuracy, what exactly is it? Is it a "use" item? IE, I select Use then select Shaymin? I don't know how to make such items yet, as this item wouldn't close the bag, then run a script like the items we have been able to make so far.
I DO know however, that Shaymin's forme also carries time elements, so you don't need to worry about telling me that!
For these formes to work, I need to find/create some sort of free space inside the Pokémon data, somewhere to store for each individual pokémon what forme it currently has. We can't use Castform's way of doing it, because Castform is strictly only in battle, while Deoxys' style simply reads the game's ROM header to determine what sprite it should load.
I've looked for a while with no success. The only pseudo-free space I could find were bits and bytes here and there and the contest data (which is technically free space on FR). Any thoughts?