Bill seems to be zapped with fairy-light when he’s in the fairy safe place. In season 3, Claudine accused him of killing Sookie to get her light. In season 6, Sookie zapped him so he wouldn’t kill Warlow and steal his light. It was Sookie who made it possible for him to gain entry the first time with her blood in him, the second time, she brought him there using her light. The first time he was there, it was light, but this time, darkness fell just as it did when he came into Sookie’s hospital bed in S3E8. Is the main difference the blood that runs through his veins?