>>19345010I'm actually doing a similar project. A couple for every Pokémon and formes. The list you posted isn't totally right.
718 base Pokémon.
Megas doesn't count because it's an in battle form. Same for Castform, Cherrim, Darmanitan, Meloetta, Aegislash and, actually the opposite, Xerneas.
Shaymin is timed so i don't know about storing it.
Furfrou has a similar problem due reverting to its original forme when in box.
Arceus, Giratina, Genesect have the same problem due to being item related.
Don't know about Burmy, as the forme will change as you take it to battle. Same for Deerling and Sawsbuck, but i think you can do it since in this gen they dropped seasons.
Vivillion is probably the biggest problem, since formes are region locked. You should hope for someone playing those regions with a different language from its country.
844 - 24 = 820 roughly for 2 because of gender makes it 1640 (actually i recall it being something around 1300-1400). Multiply this by Shiny (x2) and language (x7). 23k is big.