The immediately obvious (King of Pain) cast aside, a permutation of both words yields "King Pain," or "kingpain" if you will, which bears a phonetic resemblance to "kingpin;" while this is an interesting analysis, and Pain King, most definitely, could be considered a kingpin of sorts, the method by which the "kingpin" conclusion was arrived seems too amorphous to be a method in which excessive confidence should be placed.
Confidence: 20
