Saturn as Atmakaraka

The idea of evil or good for lagna means it can support raja yogas or disrupt them. Every planet is important for some good functioning of our life. Unless you are doing these yogas, you should ignore this concept. 

This designation of good or evil is only for purposes of some yoga determination. Unless using wht those yogas its best to ignore the idea as it will just be confusing. Every planet has an important and needed aspect to it and its always good for that thing.