In light of Dexit, I'm more curious than ever how the transfer of pokemon from gen 3 all the way to gen 7 worked. Especially gen 4's and Gen 6's transfer method given the different hardware and software used.

I understand pokemon bank is a cloud service for the pokemon data, but I wonder if there's a way to replicate or make a alternative to the Pokemon bank and Pokemon Home services?

Especially with the quality of the games and the series as a whole becoming shrouded in controversy and coming into question.

I think Pkhex could help greatly in understanding and or replicating these processes, but Pkhex might need some modifications and tweaking in order to get a better idea.

I've been researching myself, but I've come up with little results on how pokemon transfer works, anyone got any information themselves?