Ideas on how to go about this?

[Xeno Seraph]

I'm trying to get a chansey with Armoatherapy and Seismic Toss. Is this possible in Diamond? Or is the only way to do this in another game and then Pal Park the Chansey? ST isnt a TM. And The breeding seems confusing so let me know if there's a way for this to work out.

[SuperSimon]

You need to breed aroma therepy onto a chansey on emerald, then use the move tutor to learn seismic toss

[Bulbasaurus Rex]

It is impossible for Chansey/Blissey to learn Seismic Toss without Pal Parking it from a 3rd gen game.