Pokémon association

So I was basically looking at the four mythical pokémon aka victini meloetta genesect and keldeo and for the sake of it forces of nature and I associate them all with the original black and white because that's the only place you can officially get them, but you can trade most of them to B2W2. But then I looked a more at keldeo, and as both games have the event where you can get secret sword but only B2W2 gives you the resolute form so I thought what about the others? Which game would they actually associate in if it wasn't for trading/events?

Personally I think victini is for the original black and white as you need the Liberty pass which is exclusive to the originals, same way I think genesect associates with​ B2W2 As it also was an exclusive pre-order bonus and I'm pretty sure the originals didn't have any mystery gifts tied to that anyways. Keldeo is obviously B2W2 because of its resolute form. The forces of nature I associate with B2W2 because of their alternate forms. But the only one I can't figure out is meloetta because both games needed it to be gifted/events only and they both have the same in-game events too.

What do you guys think? Where would you associate these mythicals?