Let's say someone had two DS and two pokemon games like platinum and heartgold and one of them didn't have the national pokedex, say platinum. If the other game traded a feraligatr to platinum what would happen?
Nothing, it won't say it's number when you view your pokemon and it won't register in your pokedex until you get the national pokedex.If you want to trade it back it won't register in your pokedex.