Which redeemed villain deserves a spanking, maybe they ask for it, or it something another pony demanded.
List(might be more)
Luna/nightmare moon
Gilda
Trixie
Discord
Flim flam brothers(are they reformed?)
Starlight
Stygian
Tempest
Grand Pear (lol not really a villain more of an antagonist but I guess Granny Smith would be one too)
Anyone else?
Any other punishments besides spanking?

Trixie, on principle.

I don't know what she did, but she knows what she did and she should be ashamed of herself.

Luna might ask for it if she was still feeling guilty.

6302864

>Any other punishments

Bee stings to the butt are funny and erotic. At least, to me they are. You can give them a few welts, then add the spanking to top it off!