K, thanks everyone

so to reaffirm what your saying, i can trade any pokemon even from old generations, as long as i trade with another diamond or pearl?

but if i can only migrate after i have beaten the elite 4, then restarting would not allow me to retrieve the pokemon back, even if i traded to a lets say someone with diamond.

am i right?

Okay, so this is my situation:

I have pokemon diamond, and I have the national dex.

I want to restart and play through with a new party of pokemon that I wrote up.

I want to be able to get all these pokemon at the very start or near the very start of the my restarted game, and preferably at low levels, such as lv.5 like the starter pokemon.

Here is the list:

Torterra - start with obviously, not a problem

Aron

Nidoran - male

Dratini

Charmander

Larvitar

I have friend with a GBA-SP playing fire red, another friend with DS playing sapphire, and I have a third GBA-SP at my disposal

Can I migrate pokemon from those versions before i get the national dex?

Can Sapphire trade pokemon wirelessly with diamond?

There are a ton of questions that are just rattling my brain to figuire this out

I want to know what I have to do to get all these pokemon, please help.