What happens if you buy dlc's characters and then the dlc?

If you have one character but not the other,you're probably better off to just buy the other with shards or something. Especially if you don't care about cosmetics. None of the ones you get are all that amazing anyways. It's definitely cheaper to buy the whole DLC then to buy the characters separately. I ran into a similar situation. I didn't have any of the DLCs until recently. I bought two characters with shards,bought the rest of the packs,then just bought the other two missing characters with cells,which wasn't the best way to do it.

Okay so if you have both characters from a DLC chapter and then bought that DLC chapter,in a few instances you would get absolutely nothing. But some of the characters come with an alternate outfit you get for buying the DLC. As far as I know they are all commons. Nancy comes with a Wafer Sweatshirt and Torn Sweatshirt for example. Laurie has alternates for all three slots,hair,shirt,pants. Zarina has a jacket with a different color scarf. The DLC usually says if it includes an outfit,I'm pretty sure. But like I said,they are all commons to my knowledge,none of them are all that great either. So if you have the characters it's pretty much a waste of money,unless you want to pay $8 for a common outfit,which is about what it would cost to get a rare outfit from the shop.