For those who are thinking about joining up, be sure to do your homework first. Forewarned is forearmed. There are any number of websites that will give you advice on how to sell your soul, from which devil is least likely to cheat you, to what interest rates you might expect. I’m not going to recommend a particular one, as it is very difficult to verify their claims, but if you decide to go this route, Google is your friend.
You can read about Kitta here, which combines two Swedish folk tales. In the first, the devil is unable to create discord between newlyweds, but Kitta is able to accomplish it in one visit, thus winning her bet with the devil, which was a pair of shoes. In the second story she is showing off her shoes to a merchant who has sold his soul, and helps the merchant trick the devil out of collecting it. There are other stories about how she tricked the devil over a bet on a race, and how the devil was so afraid of Kitta that to deliver the shoes he stood on the opposite bank of a river and handed the shoes across on a pole.
She is also known as Kitta Grå, Katie Grey, Titta Grå, Skoella, Skokäringen, and Captain Elin/Captain Eli. The Swedish Wikipedia entry for Sko-ella tells us that this was a common saga for children in the 1400’s and 1500’s, and has a list of churches with images of Kitta. You can see photos of some of the church paintings here (Swedish language). And another church painting of Skoella here. For international folktale buffs, the text is at AT 1353. See also the AT database (Aarne-Thompson-Uther Classification of Folk Tales – database), and some classification of the Kitta tales at Swedish Legends and Folktales by John Lindow.
Below: Kitta was so evil the devil would not touch her with a 10-foot pole.